I rarely visit the Swap Meet for a reason. Its because I don't often feel I want to sort through everything on the chance I'll find something I'm looking for.
I have some keyword searches running on eBay looking for some of the things I want. But I am aware that my searches are not getting everything I might be interested in. For that reason I find it helpful to see what others have found on eBay. I'm currently bidding on something someone else pointed me to.
Another board I often visit does have an eBay forum and I find I don't often poke my nose in to see what's available.
Why? Because I'm more interested in the dialogs about trucks and truck issues than I am in seeing what parts someone is selling.
I checked Ray's eBay link and gave some thought to bidding. Then decided I'm not ready to advance my '52 GMC to the parts gathering stage (parts storage is a problem) yet, so let it go. If it had been posted in an eBay forum I'd have missed it entirely. I was not offended to find that link in a general forum.
But if the general forum were full of items for sale it could become difficult to find the threads I'm interested in reading and having a part it. Yes I am interested in some of the items offered, but like the swap meet much of the items are not ones I have any interest in at all.
So for whatever its worth, I'd prefer keeping the 'no ads' policy for the general forum. If an eBay forum were added, I'd read it from time to time, and might even use it. But I'd have the freedom to choose when I wanted to sort through that stuff, and not need to sort it out to find those things I do want to see.