FakeSignupFilter: Signup quality gate

Automatically flags disposable emails and fake signups so SaaS teams see real growth

Problem

A SaaS founder discovered over 40% of early signups were disposable emails from Mailinator, temp-mail and unknown domains, inflating user counts and distorting activation and marketing decisions. Free plans get abused, yet teams lack a low-cost way to filter before the damage is done.

Solution

A signup quality API plus a lightweight dashboard: validate email domains against disposable/temporary lists in real time at signup, score each registration, and summarize weekly real signup trends. Connect via webhook to existing signup flows without database changes.

Users

Early-stage SaaS founders, growth leads, indie developers

MVP

Disposable domain list with scoring API; webhook integration examples (Node/Python); weekly signup quality dashboard; inflated-signup breakdown by acquisition channel; one-click export of suspicious accounts.

Revenue

Usage-based pricing per verification with 500 free monthly; team subscription includes dashboard and weekly reports.

Why now

Freemium and AI tools make fake signups worse, and founders increasingly care about real retention. A lightweight API plus dashboard is a two-week solo build.