Apollo.io

Apollo.io is an all-in-one sales intelligence and engagement platform providing B2B contact data, company information, and automated outreach sequences — enabling sales and marketing teams to find prospects, enrich leads with contact details, and execute multi-channel outreach campaigns from a single platform. Founded in 2015 by Tim Zheng and Ray Li in San Francisco, Apollo.io has raised over $250 million and serves over 160,000 companies — from individual SDRs to enterprise sales teams — who need accurate contact data and prospecting workflow tools at competitive pricing.\n\nApollo's database contains over 270 million B2B contacts with work emails, phone numbers, LinkedIn profiles, and technographic data about the companies they work at. The prospecting engine enables filtering by job title, company size, industry, technology stack, growth signals, and funding status to build highly targeted prospect lists. Apollo Sequences automates multi-step outreach (email, LinkedIn, phone) with AI-personalized messaging, tracking opens, clicks, and reply rates to optimize conversion.\n\nIn 2025, Apollo.io is one of the fastest-growing sales tech companies, competing with ZoomInfo (the enterprise incumbent), Outreach, Salesloft, and Clay for sales prospecting and engagement platform share. Apollo's competitive advantage is its aggressive pricing (significantly cheaper than ZoomInfo for similar contact data) and its all-in-one design that bundles data and engagement — where ZoomInfo data must be purchased separately from engagement tools. The 2025 strategy focuses on improving data accuracy and freshness (a key differentiator from competitors), launching Apollo AI for automated outreach personalization, and growing its enterprise customer segment with SSO, advanced admin controls, and CRM sync capabilities.