I personally don't find it creepy at all, however, it may depend on how your site privacy policies are setup and what kind of product it is. I could possible se

I personally don't find it creepy at all, however, it may depend on how your site privacy policies are setup and what kind of product it is. I could possible see how some people may not want to be offended, although I wouldn't classify that under "creepy", but just more of "don't want to be bothered." Maybe, if they have an account page for the startup, add something in their settings that says "opt in for email feedback" (that's bad phrasing, but you know what I mean) so you know which users are okay with giving back feedback and don't mind being contacted.