That is a subject I have pondered over and posted on other threads. I know most members are fair but you do have some cleaver stealth dealers out on the net as well. Like I was saying on another thread, all you have to do is type in a search for a popular gun and a lot of results will be from forums of all types including Marlin Owners. That is one way I found this forum. I was searching for a Marlin 1894 in 41 cal. and it popped up a thread about one on this forum. I revisited latter and found even more threads with some having a link to an auction or a dealer. I didn't secure a rifle that way, but I did find out what I wanted to know and joined the forum at a later date.
Like I said before it is like baiting a hook and letting it drift, it spreads very fast on the internet current. The more popular the model the more results will be displayed. If I were selling a gun and wanted some good exposure it would be very easy to slip in a number of posts on several forums and let it spread like fire. For the seller it is good but for someone wanting to buy at a fair price on a particular gun it is not so good. Supply and demand goes by popularity of the item. On the internet it goes crazy.
I would rather see the auction sites do their own advertising work to sell for the persons who pay the fees for that service. And when I am looking for a gun I want, I can do my own searches to find it easy enough anyway.