"Wufoo + Free Incentivization = Cheap, Effective User Surveys" https://www.kalzumeus.com/2010/01/17/wufoo-free-incentivizat... (No HN discussion)
"Your first ten customers: How should you communicate with customers?" https://stripe.com/atlas/guides/starting-sales#how-should-yo... (HN discussion https://news.ycombinator.com/item?id=15534034 598 points | Oct 23, 2017 | 133 comments)
Can I add my own advice: In a previous post you said that you are using surveys. How long are them? I have very little patience and I'd answer only 2 or 3 questions, like
* Do you have any comment or feature request?
* Email/phone to ask more about this. (optional)
* [Not enough patience. I ignored the third question and closed the browser!]
Probably people has more patience than me, but try to make it short.