Hi, here's the old FAQ:
http://www.arielarchives.com/brett/FAQ.html#2
It was a typical informal bidding list. Fun, but I personally had too many security concerns from a similar field (selling Magic: The Gathering stuff online) to use it. It made for good reading and was fun to watch, nice tight-knit community where revelations would sometimes appear as items popped out of the woodwork. Serendipitous research, as it were.
Honestly its primary use to me was in gauging levels of interest in game materials, so I'd know what to buy, trade and sell at the cons. The lack of a centralized venue/clearing house made it pretty shady at times. The honest people kept it clean, but there were a few explosions as there always seem to be.
eBay isn't much better, really, with the fees and lazy policing. I still prefer face-to-face dealings with big collections.
The spirit of the list still exists, actually, for those who prefer that approach; it simply takes the form of private deals sometimes coordinated through this site's mail system.