Apollo.io
AI-native sales engagement platform — an end-to-end go-to-market system that combines a proprietary B2B contact database (275M+ contacts, 73M+ companies) with sequencing, dialer, meeting scheduler, deal management and an AI Assistant that books meetings, drafts outreach and runs conversation intelligence on calls. Founded 2015 in San Francisco by Tim Zheng, Ray Li and Roy Chung as ZenProspect; rebranded Apollo.io in 2018. Built on a product-led-growth funnel with a free tier and self-serve conversion into paid seats, layered on a multi-model AI Assistant routed across OpenAI and undisclosed peers, with Apollo’s contact-data-and-sequencing layer as the workflow surface for revenue teams.
The Business
Apollo.io is an AI-native sales engagement platform — an end-to-end go-to-market system that combines a proprietary B2B contact database (275M+ contacts, 73M+ companies), sequencing, dialer, meeting scheduler, deal management and an AI Assistant that books meetings, drafts outreach and runs conversation intelligence on calls. The company was founded in 2015 in San Francisco by Tim Zheng (ex-LinkedIn, ex-Microsoft), Ray Li and Roy Chung as ZenProspect, and rebranded Apollo.io in 2018 after a multi-year pivot from a recruiting-tools company to a sales-engagement platform. The product is anchored on Apollo’s contact-data-and-sequencing layer — the proprietary B2B contact database that sits above a multi-model AI Assistant routed across OpenAI and undisclosed peers, with sequencing, dialer, meeting scheduler and conversation-intelligence workflows as the engagement layer on top. Apollo is sold to revenue-operations, sales and growth buyers on a freemium-plus-per-seat consumption model with paid plans from $59 / user / month (Basic) through $99 / user / month (Professional) to custom enterprise pricing; the PLG funnel with self-serve conversion into paid seats is the dominant top-of-funnel channel. Apollo is an independent, founder-led company with cumulative ~$251M raised through an August 2023 Series D at a $1.6B post-money valuation led by Bain Capital Ventures, profitable per most reporting; the relevant financial frame is Apollo ARR ($150M as of May 2025, up 9x in the two years pre-Series D) with the post-Series D valuation framing as context.
Customers and Distribution
Apollo discloses 500K+ companies in the funnel, 5,000+ paying customers and 3M+ GTM professionals on the platform — an unusually self-serve-heavy customer profile for the sales-engagement category that directly reflects the PLG-first go-to-market motion. The customer mix skews toward SMB and mid-market revenue teams across consumer and B2B verticals, with a growing enterprise segment as the AI Assistant capabilities mature. Distribution sits across three principal motions: a self-serve product-led growth funnel driven by the freemium tier (the dominant top-of-funnel channel, with 500K+ companies in the funnel as the structural signal that the PLG motion has reached category-defining velocity), direct sales for the mid-market and enterprise tier (the post-Series C and post-Series D scale-up motion), and a partner-integration ecosystem that includes Clay, n8n, Zapier and Salesforce on the workflow side. The AI Assistant lifts meetings booked by 2.3x per Apollo’s product disclosure, which is the structural signal that the bundled data-engagement-and-AI stack is compounding inside the customer base. The $0 to $150M ARR trajectory in roughly seven years from founding to May 2025, with revenue 9x over the two years pre-Series D and continued profitability across 2024-2025, is the basis for the P1d time-to-revenue stage-appropriateness sub-rubric at 9 and the P3c GTM-maturity sub-rubric at 8 in the v1.6 evidence pass.
Model Strategy
Apollo.io is a Verticals-first generative-AI play: the strategic bet is that vertical sales-engagement-and-data infrastructure with deep integration coverage — a 275M+ contact database, a sequencing-and-dialer engine, an AI Assistant that drafts outreach and runs conversation intelligence, CRM-sync history and Clay-and-n8n-and-Zapier pipeline integrations — beats generalist outreach copilots and stand-alone data providers inside SMB and mid-market revenue-operations procurement. The foundation-model stack is deliberately multi-supplier: a router across OpenAI and undisclosed peers with selection driven by latency, cost and capability per AI-Assistant task (the model mix is not publicly disclosed, which is the basis for the D4a supplier-diversity sub-rubric at 6 in the v1.6 evidence pass). The infrastructure layer is cloud-hosted with the standard SaaS-data-residency posture for the data-enrichment category. Above the foundation-model layer, Apollo’s contact-data-and-sequencing surface is the workflow layer; per-seat plus credits-based consumption is the monetisation surface; the 275M+ contact database plus the sequencing-and-AI-Assistant stack plus the PLG funnel with the freemium tier are the structural differentiators. Output and workflow portability are constrained by the customer-specific sequencing configurations, the CRM-sync history and the credits-based consumption architecture — the same workflow-embedded lock-in that anchors sales-engagement-platform retention in the data-and-engagement category (the D1c portability sub-rubric was held at 6 on that basis).
At A Glance
The Numbers
Annualised revenue
Leadership Team
Apollo.io appointed Matt Curl as CEO in February 2026 per Revenue Brew (Revenue Brew, 18 Feb 2026); co-founder Tim Zheng transitioned out of the CEO seat to a chairman / founder role (exact title pending primary Apollo disclosure). The three-founder bench (Zheng, Li, Chung) has been intact since the 2015 founding and through the 2018 ZenProspect-to-Apollo.io rebrand and the August 2023 Series D; the February 2026 CEO transition is the first non-founder appointment at the top of the executive layer. Senior commercial recruiting has scaled with the headcount expansion to ~1,600 employees but the company has not yet publicly named a separate CFO appointment distinct from the founder bench at the post-Series D scale. The D4e key-person dependency sub-rubric reframes around Matt Curl’s bedding-in as CEO and the founder-team’s continued load-bearing role on product direction. Apollo’s go-to-market motion is anchored on a product-led-growth funnel with a free tier and self-serve conversion into paid seats — an unusually self-serve-heavy motion for the sales-engagement category that directly reflects the founder team’s product priorities.
IM Framework Scoring
IM’s structured assessment of Apollo.io’s competitive position. The summary below is the headline; expand “Show the full analyst-grade analysis” near the bottom for the per-dimension reasoning and evidence. Methodology →
Funding History
| Date | Round | Raised | Post-money | Lead investor(s) |
|---|---|---|---|---|
| Aug 2023 | Series D | $100M | $1.6B | Bain Capital Ventures |
| Mar 2022 | Series C | $110M | $900M | Sequoia Capital |
| Oct 2021 | Series B | $32M | undisclosed | Tribe Capital, NewView Capital |
| 2018 | Series A | ~$7M | undisclosed | Nexus Venture Partners |
| 2016 | Seed | ~$2M | undisclosed | Y Combinator, SV Angel |
Cumulative ~$251M raised through the August 2023 Series D at a $1.6B post-money valuation led by Bain Capital Ventures, with continued participation from Sequoia, Tribe Capital and NewView Capital. Round-by-round figures from Apollo’s own magazine and blog, TechCrunch, Sacra’s company analysis and Forbes coverage. The Series D landed at a 9x ARR multiple on the $150M+ ARR trajectory and no new round has been disclosed across 2024-2025, consistent with the capital-efficient PLG motion and the profitability reporting.
Competitive Landscape
Apollo.io’s competitive set sits in three concentric rings: the structurally symmetric data-and-engagement incumbents (ZoomInfo on the data side, Outreach and Salesloft on the engagement side) that bring materially larger enterprise install bases, the CRM-platform-embedded symmetric play (HubSpot Sales Hub plus Breeze AI) that competes from a larger SMB-and-mid-market install base, and the canvas-and-orchestration flanking play (Clay) that mirrors the data-plus-outreach combination at a higher data-orchestration ceiling. Apollo is unusual in the set because the competitive frame is the bundled contact-data-plus-sequencing-plus-AI-Assistant stack delivered through a PLG funnel rather than the modular per-layer purchase pattern — the strategic bet is that an integrated data-engagement-and-AI workflow at a self-serve price point beats stand-alone data providers or engagement platforms inside SMB and mid-market revenue-operations procurement.
| Competitor | Positioning | Distribution edge | Threat profile |
|---|---|---|---|
| Clay | AI-native go-to-market platform anchored on a programmable spreadsheet-style canvas that orchestrates 100+ data providers and LLM-driven research — a flanking play that mirrors Apollo’s contact-data-and-outreach combination from a canvas-and-orchestration angle at the mid-market and enterprise tier. | Direct mid-market and enterprise sales; self-serve product-led growth motion; the Claygency partner network on the implementation-services side. | High — structurally symmetric play with a materially overlapping mid-market install base; the principal head-to-head where data-orchestration-plus-outreach budgets compete with Apollo’s contact-data-plus-sequencing stack. |
| ZoomInfo (ZoomInfo (NASDAQ: ZI)) |
Public-company B2B data and intelligence incumbent — the dominant contact-and-account-data provider that Apollo’s data-and-engagement combination competes with on data breadth and that Apollo’s customers often run alongside Apollo at the enterprise tier. | Direct enterprise sales; established Fortune 500 customer base; Salesforce AppExchange channel; partner ecosystem with revenue-operations consultancies. | High — structurally symmetric data-incumbent play with a materially larger enterprise install base; the principal head-to-head on data breadth and on enterprise procurement. |
| Outreach | Sales engagement platform anchored on outbound cadence orchestration and revenue-team workflow — the established enterprise incumbent in the engagement-and-cadence layer that Apollo’s sequencing workflows compete with at the enterprise tier. | Direct enterprise sales; Salesforce AppExchange channel; established Fortune 500 customer base; partner ecosystem with revenue-operations consultancies. | Medium-High — engagement-anchored incumbent with a materially larger enterprise install base; the principal flanking risk where Apollo’s sequencing-and-dialer workflows compete with Outreach’s cadence layer. |
| Salesloft | Sales engagement platform anchored on cadence orchestration and conversation intelligence — the second engagement-layer incumbent that Apollo’s outreach-plus-call-recording stack competes with at the enterprise tier; private-equity-owned (Vista Equity Partners acquired 2022). | Direct enterprise sales; Salesforce AppExchange channel; established mid-market and enterprise customer base; partner ecosystem with revenue-operations consultancies. | Medium-High — symmetric engagement-layer play with a Vista-anchored enterprise install base; the principal head-to-head on cadence and conversation-intelligence procurement. |
| HubSpot (HubSpot (NYSE: HUBS)) |
Public-company CRM-platform-embedded symmetric play on the SMB and mid-market tier — HubSpot Sales Hub plus Breeze AI competes directly with Apollo’s data-and-engagement combination at the lower end of the customer pyramid. | HubSpot CRM enterprise install base (200,000+ customers); Sales Hub channel; partner ecosystem; bottom-up product-led-growth motion. | Medium-High — CRM-platform-embedded symmetric play with a materially larger SMB-and-mid-market install base; the principal flanking risk where Sales Hub and Apollo budgets overlap. |
Pricing benchmark: Apollo.io anchors at a freemium tier with paid plans from $59 / user / month (Basic) through $99 / user / month (Professional) to custom enterprise pricing, sold on a per-seat plus credits-based consumption model. ZoomInfo and Outreach use enterprise per-seat plus consumption pricing at materially higher published list prices. Salesloft pricing is comparable to Outreach on the engagement side. HubSpot Sales Hub layers a per-seat pricing model on top of the HubSpot CRM subscription. Clay is sold at a higher mid-market and enterprise per-seat-plus-credits price point. The competitive frame is therefore self-serve-PLG access plus the bundled data-and-engagement combination rather than headline per-seat price; Apollo’s structural differentiator is the 275M+ contact database plus the sequencing-and-AI-Assistant stack plus the self-serve free-tier funnel that drives 500K+ companies into the top of the funnel.
Potential Risks
The case for Apollo.io at IM Framework 6.99 rests on the bundled contact-data-plus-sequencing-plus-AI-Assistant stack delivered through a product-led-growth funnel as the structural moat, 500K+ companies in the funnel and 5,000+ paying customers as anchor references, a $251M cumulative raise through a $100M Series D at $1.6B post-money valuation led by Bain Capital Ventures, and a capital-efficient profitable trajectory at $150M ARR (May 2025). The case against splits into five risks of differing magnitude — with the symmetric-competitor cadence the most active, the data-enrichment regulatory load the most policy-driven, the foundation-model supplier dependency the most supplier-side, the vertical-product framing the most structural, and the founder-concentration the most distinctive governance pattern in the score.
Symmetric competitor pressure — Clay, ZoomInfo, Outreach, Salesloft, HubSpot
Apollo’s most direct competitive risk is from Clay (canvas-and-orchestration flanking play with a $1.3B+ Series C), ZoomInfo (public-company data incumbent with a Fortune 500 install base), Outreach and Salesloft (engagement-layer incumbents with enterprise customer bases) and HubSpot (CRM-platform-embedded symmetric play with a 200,000+ SMB-and-mid-market install base). The structural risk is not that any one rival beats Apollo head-to-head — the 500K+ company funnel, the 5,000+ paying-customer base and the self-serve PLG motion are durable — but that the symmetric-competitor cadence compresses per-seat plus credits-based pricing and slows the ARR trajectory below the $1.6B valuation implied path. The bull case is that the bundled data-engagement-and-AI stack at a self-serve price point compounds against modular rivals; the bear case is that Clay’s data-orchestration breadth and HubSpot’s CRM-platform leverage close the gap.
Regulatory exposure — GDPR, CCPA and EU AI Act
Apollo is a data-enrichment business anchored on a 275M+ contact database with public-web-data and contact-data sourcing as the upstream input. The principal forward risk is GDPR and CCPA exposure on B2B contact-data acquisition, growing regulatory pressure on data-scraping discipline in the EU and California, and EU AI Act general-purpose-AI obligations from Aug 2 2026 on the multi-model AI Assistant stack. The D4c regulatory-exposure sub-rubric was held at 4 in the v1.6 evidence pass on the structural GDPR exposure plus the sector-wide trend toward more restrictive B2B contact-data rules. The bull case is that the SMB-and-mid-market customer mix is materially less regulatory-sensitive than Fortune 500 enterprise procurement; the bear case is that any enforcement action against a B2B contact-data acquirer has downstream procurement and brand consequences across the category.
Foundation-model supplier dependency
Apollo runs a multi-model AI Assistant architecture for the conversational-AI, draft-and-summarise and conversation-intelligence features — the model mix is not publicly disclosed but the architecture is partial mitigation of supplier-concentration risk. The D4a supplier-diversity sub-rubric was held at 6 in the v1.6 evidence pass on that basis. The asymmetric overlay is that the foundation-model layer is rapidly commoditising at the capability frontier — which is partially de-risking for a vertical sales-engagement aggregator like Apollo (more supplier choice, falling inference cost on the AI Assistant features) and partially threatening (foundation-model providers ship adjacent outreach-and-sequencing capability directly via agentic interfaces, and the model layer is portable in a way the workflow integrations are not).
Vertical-product framing — no foundation-model layer of its own
Apollo is a vertical sales-engagement-and-data application built on top of third-party foundation models — it does not own a frontier model and does not benefit from the network-effect compounding that horizontal platforms can claim. The durable moat is the 275M+ contact database, the sequencing-and-dialer engine, the CRM-sync history, the Clay-and-n8n-and-Zapier pipeline integrations and the embedded-workflow lock-in inside revenue-operations procurement rather than model capability (the D1c portability sub-rubric was held at 6 on that basis). The bull case is that contact-data depth plus the sequencing engine plus the PLG funnel are themselves the moat, and that the procurement dynamics of sales engagement favour vertical specialists. The bear case is that as CRM-platform incumbents (HubSpot, Salesforce) ship better out-of-the-box data-plus-engagement capability and foundation-model providers ship better agentic outreach, the vertical layer compresses.
Founder-concentration and executive-bench depth
Apollo appointed Matt Curl as CEO in February 2026 per Revenue Brew, with co-founder Tim Zheng transitioning to a chairman / founder role; the three-founder bench (Zheng, Li, Chung) has been intact since the 2015 founding through the 2018 ZenProspect-to-Apollo.io rebrand and the 2023 Series D, and no separate CFO has been publicly named distinct from the founder bench at the post-Series D scale. The D4e key-person dependency sub-rubric reframes around Matt Curl’s bedding-in as the first non-founder CEO and the founder-team’s continued role on product direction; the v1.6 evidence pass score was held at 5 pre-transition and warrants a re-score post-Curl arrival. The bull case is that the founder-team brings continuity and direct accountability to the PLG funnel and the SMB-and-mid-market buyer set; the bear case is that CEO-transitions at $150M+ ARR scale are non-trivial and Curl’s early commercial cadence plus any disclosed CFO appointment over the next 12 months are material watch-items.
Recent IM Coverage
Show recent press coverage of Apollo.io
- Feb 2026 — GTM platform Apollo.io is making changes at the top — Matt Curl named CEO; Tim Zheng transitions to founder / chairman role.
- May 2025 — Apollo.io reaches $150M ARR — sales-engagement platform crosses the milestone on a 9x two-year trajectory.
- Aug 2023 — Apollo.io secures $100M Series D at $1.6B valuation to drive world-class GTM.
- Aug 2023 — Apollo.io raises $100M Series D led by Bain Capital Ventures at $1.6B valuation.
- Mar 2022 — Apollo.io raises $110M Series C led by Sequoia at $900M valuation as PLG funnel scales.
- 2024 — Apollo.io company analysis — ARR trajectory, customer breakdown and Series D context.
- 2025 — Apollo AI Assistant lifts meetings booked by 2.3x — product page disclosure on the AI-engagement workflow.
- 2025 — Apollo sales engagement product page — sequencing, dialer and AI Assistant workflow stack.
- 2025 — Apollo.io G2 reviews — 8,000+ verified reviews on the sales-engagement category leaderboard.
Curated feed of named-source coverage — Apollo’s own magazine and product pages, named-author technology and business press (TechCrunch), and analyst coverage (Sacra company page, G2 reviews). Excludes paywalled article bodies of The Information, WSJ, FT and Bloomberg (headline plus free-snippet only), PR-wire reposts of the same release and unsourced AI round-up pieces.
Show the source register for the figures on this page
IM operates a primary-source-where-possible discipline. The figures above come from:
- Revenue: Apollo reported $150M ARR as of May 2025 per Sacra’s Apollo company analysis, with the underlying trajectory at $96M ARR (end 2023) rising to $134M ARR (end 2024, +40% YoY) before reaching the May 2025 figure. Revenue 9x over the two years pre-Series D per the same Sacra analysis. Apollo is profitable per most reporting; the company has not disclosed a precise EBITDA or operating-margin headline figure.
- Customers and deal-mix: Apollo discloses 500K+ companies in the funnel and 5,000+ paying customers with 3M+ GTM professionals on the platform per the Apollo product page and the Apollo Series D announcement. Channel mix is product-led growth driven by the free tier and self-serve conversion into paid seats (the dominant top-of-funnel channel), direct sales for the mid-market and enterprise tier and a partner ecosystem on the integration side (Clay, n8n, Zapier pipeline integrations). The AI Assistant lifts meetings booked by 2.3x per Apollo’s product disclosure.
- Headcount: Apollo reported ~1,000 employees as of the August 2023 Series D, rising to ~1,600 employees by 2025 per Sacra’s Apollo analysis and LinkedIn-visible company-page data. Senior engineering and go-to-market hiring tracking the post-Series D scale-up; the senior team is developing as the company scales past the $150M ARR milestone.
- Funding to date: Cumulative ~$251M raised through the August 2023 Series D at $1.6B post-money per Apollo’s own Series D announcement, with corroborating coverage in TechCrunch and Sacra’s Apollo analysis. The Series D was led by Bain Capital Ventures with continued participation from Sequoia and Tribe Capital; the March 2022 Series C was led by Sequoia at $900M post-money; the October 2021 Series B was co-led by Tribe Capital and NewView Capital at $32M. No new round has been disclosed across 2024-2025, consistent with the capital-efficient PLG motion and the profitability reporting.
Methodology & Disclaimer
For metric definitions, source-tier hierarchy, and decline-to-publish rules, see the tracker methodology. Confidence dots (• green / • amber / • red) follow the same convention as the AI Tracker.
Spotted a figure you believe is wrong? Send corrections to info@informationmatters.net.
Information Matters Framework scores are the considered opinion of the IM team — human and AI — applied to publicly-available evidence under a disclosed methodology. They are not statements of fact about the companies scored and they are not investment advice.
