Apollo.io

Apollo.io combines a B2B contact database (275M+ contacts) with email outreach and CRM features. Search for leads by job title, company size, industry, and tech stack. Export emails, run outreach sequences, and track engagement — all in one platform. Free tier includes 10 mobile credits/month and limited search, enough to test. Paid plans unlock bulk export and sequences.

Ideal for B2B sales teams, SDRs doing cold outreach, and growth teams at startups. If you're selling to specific personas (e.g., "VPs of Engineering at Series A SaaS companies"), Apollo finds them and provides verified emails. The built-in sequencing means you don't need separate tools for prospecting and outreach. Data quality beats most cheaper alternatives.

Downsides: enterprise pricing for advanced features, data coverage is weaker for smaller companies and non-US markets, and the CRM functionality is basic (you'll want a real CRM for deal management). ZoomInfo has deeper data but costs 3-5x more. For startups doing outbound, Apollo hits the sweet spot of quality and affordability.