A lead is a person or company that has given you a reason to believe they could buy: a form fill, a trial, a referral, or a match with your ideal customer profile. The reason sets the grade, from cold to marketing qualified, sales qualified and product qualified. A lead is only usable if you can reach it; across 6.5 million business addresses verified in 2026, 14.5% were invalid and a further 27% could not be confirmed.
Leads are counted at the point they enter a system, which makes the count easy to inflate. A bought list of 10,000 rows is "10,000 leads" in a spreadsheet and perhaps 3,000 reachable, interested people in practice. Teams that measure leads honestly track three things per record: fit (does the company match the profile), intent (what did the person do), and reachability (does the contact channel work).
The grade matters more than the count. Product-qualified leads close at 20 to 40% in SaaS; marketing-qualified leads at 1 to 5%; cold leads well under 1% per email. The sales leads guide sets out the grades with their typical volumes and close rates.
A 1,000-row export from a prospecting database lands in a CRM. Verified the same day, it splits into 720 confirmed valid, 30 catch-all, 110 unknown and 140 invalid. The honest lead count for cold outreach is 720, not 1,000, and the 140 invalid rows would have pushed the bounce rate to 14%, seven times the 2% line Google and Microsoft enforce on senders.
Verify a list or a single address. 100 free checks a month, unknowns refunded.
Verify Leads - FreeAyoub built BounceZero's 5-stage validation pipeline, its dedicated BGP-announced IP infrastructure, and the Patroni HA PostgreSQL cluster behind every verification. Previously built high-volume email delivery infrastructure. Trained at 1337 Benguerir (École 42 network, 2019). Open-source: bgp_analyzer.