I've never been approached about marketing once, but I am not prolific like other users. I imagine you have to be in the top 100 or 1000 users in order to get those sorts of offers. The closest I've experienced was when I organically made a post on the speedcubing subreddit asking for opinions a new cube by a fairly unknown company and I was contacted by an employee of the company thanking me for the post and offering to give me one for free.