While checking a recent purchase, I happened to notice that I first signed on to eBay in early March 2003 - which means I've been using it for Twenty Years.
Of course it's changed a lot in those 20 years, as has my usage.
Early times it was much more a private user auction site, and in my first few years I used it extensively, loving the cut and thrust of auction bidding, and I acquired a nice bundle of collectables.
Nowadays it's mainly commercial users, fixed price with very little bidding, and I use it less than a dozen times a year, predominantly for useful items.
I've done very little selling, too much hassle packing and despatching.
I much prefer 'buy it now' listings when I'm buying. It's only this year, after 18½ years of occasionally buying things from the site, that I've sold anything on eBay (with just two sales so far). I chose to use the auction format for those because they were quite unusual items, where it was hard to work out what they might fetch.