One thing to be careful of these days when offering free-trial

I have heard from a good amount of SaaS founders how they got burned several thousands of dollars on their free-trial offer due to high AI usage costs (included in free-trial). For example, an AI image generation app usually offers some credits free but bad actors open 100 accounts to get free usage on founder's money. And its becoming easier to do this trick usign agentic swarms etc...

So be careful developers when you offer free-trial involving AI usage. There are several ways to mitigate this thing.

• One is to use Cloudflare Turnstile,
• block multiple sign-ups from same IP,
• add a $0 credit card wall at start of free-trial,
• put a limit on AI per hour bill, per week bill and per month bill ~~per user~~.

(you can ask Claude to develop the guard against such act)

I wanted to tell the community here what I learned and implemented in my SaaS learning from other founders experiences.

Author: notionized