They would've had to buy it to post here, but I can see it happening in-game.
Prior to the Auth-Key required posting we used to get topics in General Discussion with people asking why they should buy Blockland.
The same stuff was always said.
"Because you should", "Because it's only $20", "Why shouldn't you", "I don't think you deserve to buy it", etc...
There would be a few posts on what was good about it, but most of it was people either posting stupid things or saying that there's no point asking on the forums of the game you're interested in, because you're only going to get biased views.
I'm sure it happens on all forums related to games.