[natvod]

Something that I found works well is just emailing influential people who you think would really benefit from your product and asking them for feedback. Since you're not selling your product, people (even busy ones) do reply. If you built a good product, they will keep using it (and maybe even tell other people about it) and if there are kinks that need to be ironed out, that's great to know as well.

This is apparently how Ilya from Datanyze got his first customer. He cold emailed Ben (then vice president at KISSmetrics) asking for feedback (https://artofemails.com/cold-emails#feedback).

[yread]

I do this and got some good feedback but also some "is great you're interested in my services I charge 400 eur/h. Are you interested?"