Transparency. Not necessarily in who the bidders are because arguments can be made both ways - but in other fashions. As an example, and this is just one:
User Hatfield Ventures has a listing for Bundled auctions com -
https://flippa.com/5580986-125-premium-domains-aged-valuable-high-cpc-rare-bundle
He lists his name as Josh and Hatfield Ventures, and a brief internet search turns up Hatfield Ventures and Josh and their activity in the domain market. The thing is, most of the domains in that listing are registered to Jason King and do not resolve to Josh and Hatfield Ventures at all. Somehow Hatfield Ventures (Josh) is selling domains in a bundle for Jason King. Is Hatfield a broker? Flippa insider?
As well, Hatfield ventures has an impressive sales history with Flippa, doing over 98k on 5 transactions there - yet has no feedback positive or negative, and no history under their user name of the previous transactions. Hatfield's history is not prone to vetting by anyone because Flippa doesn't have it, but that is not the case for all users who buy/sell domains there. So, things get suspicious from lack of
transparency.
In order for Hatfield to sell someone else's domains as a broker he should have "Broker" labeled on his profile. His sales history is such that with his prior listings having been private, nobody knows who/what he is about. Likewise, it could be assumed by some that Jason King may have a history with Flippa and for whatever reason (ban, shill, whatever) he can still do business with people who may not wish to do business with him simply by using Hatfield Ventures as the Straw Man. Again,
Transparency.
Furthermore, using the example, people have to wonder - is Hatfield/Josh actually paying for their premium listing, was it a gimme from Flippa for Hatfields huge revenues on 5 prior transactions, or..........? Personally, I don't care what Flippa gives away and to whom they give it, that's their business- but it brings me to my second piece of feedback......
Reasonably equitable:
Using the same example above, if you go to Flippa right now and simply click on "auctions" under domains, the second listing is for the one mentioned above. It is at $300 as of this post with 2 bids and 29 days remaining. But why? Looking further down the list you can find premium auctions of better quality, lesser time frame, more bids, lesser/more money - but this one is number 2. That doesn't seem
equitable at all, and this same "flaw" for lack of more direct terms is a huge stop sign for using Flippa. It isn't
equitable when one user may be brokering domains for someone else, and getting carte blanche treatments doing so, but they don't have their history there for us to see like most others do. As well, why should someone pay top money to promote their domain if Flippa can't run an
equitable process?
Two of the top 5 listings when just clicking on "Auctions" is for user Pioneering Ventures - that indicates the user Pioneering Ventures is someone to somebody. The way Flippa employees - and be honest, Kevin - your own friends in domaining keep changing names over there at Flippa it's just too secretive, and not even remotely
reasonably equitable.
Change your default auction tab to one metric only and stick with it so people know what they're getting. You know you can't make it ' views, or bids, or amount' because those metrics can be.....influenced? Make it by ending time by default.
When lacking transparency and equity, given the website's' history, changes to costs/layout/features...etc, will be moot to most domainers here at Namepros. Flippa's bread and butter is raking revenue from new users on a pipe dream willing to lay out big money on a low value domain with dreams of riches. Eventually that market will dwindle, and if Flippa hasn't bridged the gap with Domainers as a whole, Flippa will dwindle along with it.
Good luck.
Quick Edit: Just as an FYI since I used the listings as an example above, I did learn who "Jason" the owner of some of the domains in "Joshs" listings is -
Jason is this person -
https://flippa.com/users/698100/listings