Is it a problem you actually have? Have you identified something malicious users can do of they sign up for your platform?

I think you'll see significant drop-off if you try to get people to sit through a demo. And couldn't a bot do that anyway? What are other platforms doing, because have never seen this. I hate re-captcha and would not sign up of I had to identify crosswalks either, but maybe find a captcha that doesn't hate users and try that?