Ask HN: How to stop "demo" abuses

I've been keeping efforts to implement the internet's "basic+free" SEO tips into the product, which worked. Ours is now at the top. This is the first time, I ever concentrated on SEO for any of the projects, certainly happy about the result. I want to understand the risks and precautions I should take, especially when you have a "Demo" for the trial but users are constantly abusing it with their skills. I've the very basic usage check (with a counter stored in the localStorage) limitation implemented already which is not enough. Will be helpful if someone chip-in with leads on the ways to limit the users after certain number of trails per day. Thank you.