I have some experience with Bido, and this is my objective observation:
I have to agree on the quality of the inventory. Mostly poor quality, obscure extensions. I think they may have had a much better shot if they would have enacted some sort of a screening program. Maybe something similar to their bigshot counterparts that don't just take anything rather than leaving it in the hands of the users. They should have had restrictions in place to control the quality of the inventory. It got off to a decent start, but as it gained popularity the place was flooded with junkers. There were too many inexperienced "domainers" that hoped to turn $7 into $28 or more.
I think the nail in the coffin was the voter rewards program. Too many folks voting in domains hoping for a share of the proceeds & having no intentions of bidding on them. I can remember when it would take 5-15 days just to get those 5 votes needed. Back then, more often then not, my domains sold. But when the 10 vote system (coupled w/ voter rewards) came out, domains would make it through within hours. If you allowed Bido to schedule your auction ( as I did) you'd sometimes get weird start times & fail to get any exposure. I recently submitted around 10-12 domains that were ALL voted in within 2 days & not a single sale. They weren't "legendary" domains, but by comparison they were of fair quality.
Then they changed the "completed auctions" list to "recent sales", because the sales ratio was in the toilet. A perspective user may use that list to determine whether to use the service or not. Last time I checked, they were averaging around 10 sales a day. If I were a perspective customer, I may not have thought that to be a thriving marketplace - especially after seeing the quality of the domains. Most sales were below $100. With such a low commission, they couldn't have been turning ANY kind of a profit.
I think the $28 minimum produced quantity over quality. As the quantity snuffed out the quality, buyers got frustrated with sifting through junk hoping for the diamond in the rough. If I want to spend that kind of time, I'll go to eBay.
I think they shot themselves in the foot despite their best efforts. I wish all of them the best of luck.