There are probably many factors involved in many of the "where are all the sales" threads I see regularly. I don't believe it is an Ebay specific issue, as I sell at a swap meet and the crowds have dwindled there over the years. One aspect that is unique selling in that manner is the ability to talk with dealers and buyers. Here are the reasons I see why sales are dropping:
1- More sellers. All of these reality shows have convinced a large number of people that the atic full of stuff is valuable, the trash...erm I mean treasures in storage auctions are going to buy you that mansion, etc. So more people are selling. This is resulting in a flood of "treasures".
2- More venues to sell on. Between the river, the craft site that does vintage now to the more local areas (Craigsplace, Fakebook, various apps) that slowly over the years once dominant sites like here have seen their customer base drop as others began shopping more conveniently elsewhere.
3- The hostile environment. I dabbled in selling here, and understand what it is like to be the target of scammers, which is why I only dabbled. But having said that, some sellers attitudes here are over the top, believing that the most innocent question or honest feedback is an attempt of a buyer to scam. Honestly, if you reach that point as a seller, you probably should do what I did and move on to selling in another manner. I read so much here of BBL, but for one who shops regualrly here I will tell you Ebay also needs a BSL as well, as mine has grown unmanageable. Do any of the sellers know they are on it? Nope. Isn't worth my time to mess with the drama. Shake the dust off and move on. But know these can affect you. Case in point, I used to deal with the old Atari games. After about my fifth lot of "tested' cartridges where half didn't work, I don't buy them here now. if you sell them here, won't be my money buying them.
4- Every year, more people who want vintage items for the nostalgia feeling are dying off or moving to a retirement income that no lonmger affords the same spending they had while working. Exoect this trend to grow over the years as it is my experience less and less younger people care for vintage/antiques, nor do many of the immigrants coming here.
I could go on, but the point i am making is I expect to see these same posts five years from now referring to the good old days when sales were to be had, referring to this moment right now.
