Sure I can tell you, before I had a chance to write it Jamie from DotWeekly left a comment on TLDinvestors explaining it succinctly.
Paul,
One thing to consider and a reason the bidder’s ID should be required even for expired domain auctions:
Bidder 1 places a bid
Bidder 2 places a bid
Bidder 2 drives the auction way up (using a fake account of sorts) off a proxy bid from bidder 1 and nobody else bids
Bidder 2 doesn’t pay, bidder 1 gets the domain for it’s initial bid due to the NPB. (from my understanding, GD does not re-auction domains)
I’m sure this happens and to what scale, I’m not sure. I’m sure it’s twisted more than just 1 & 2 bidders and could include 3 or 4 bidders, where the bid price isn’t always very low to throw flags.
There is no way to associate if the winning bidder got the domain after the auction. If it was renewed, second bidder got it etc. Since that is the case, it creates questions. If I can see I was bidding again a specific bidder ID and later whois records make sense, then I wouldn’t question it. Bidder 1 doesn’t help me with that.
That was a reply to Paul Nicks from GoDaddy who left a comment on the blog.
http://tldinvestors.com/2017/07/its-time-for-godaddy-to-initiate-bidder-ids-to-godaddy-auctions.html