Of course the Cellar has been infiltrated.
"
Hey guys, I found this website (that sells crap.) What do you think? I think it's..."
Does it matter? Yes.
I don't know how to fight it, other than calling people out when they start posting spam on their first day.
There have been plenty of links to commercial sites by long time posters. I have no problem with them.
I'm not sure how to distinguish the two, but it has to do with the quality of the posts and the history the dwellar builds here before posting to commercial sites. One is natural and real. The other is fake and forced.