I didn't get into details, as there are usually legalities to tiptoe around. All I know is, as a vendor paying dearly for Audiogon's services, their value proposition has just diminished greatly. Stereophile.com visitors generated a good deal of traffic for my site when I would run ads. One could run a "classified" ad on Audiogon, and essentially get very cheap advertising on Stereophile.com.
That was probably one of the reasons for the discontinuation.