How many of your signups are bots?

Someone on your team posts the sign-up number in Slack every week. Everyone reacts with a rocket emoji.

Nobody asks how many of those people are real.

Fake signups don’t announce themselves. They show up as inflated user counts, a welcome email list full of dead addresses, a free tier quietly being used by scripts, or an sms bill that spikes for no reason. By the time someone notices, the data is already messy.

And the cleanup is where it gets awkward. growth wants the numbers to stay high. Engineering didn’t build the signup form to be a filter. Security assumes someone else is watching. So the list just keeps growing, and nobody owns it.

The usual fixes sit at different layers.

Block disposable email domains, restrict phone prefixes or regions you don’t serve, add a captcha, rate limit by IP. Each one helps, and each one adds a bit of friction for real users. The earlier you catch it, the cheaper it is, since stopping a bad account before it exists beats deleting it afterwards.

Curious how teams handle this. Do you actually know what share of your signups are fake? And who owns it in your team: growth, engineering, or nobody?