Essentially it's a penny auction where bids go up by one penny but each bid costs ~ a dollar to place. Such auctions are easy to manipulate using programs as a buyer to place a winning bid at the last second but also as the seller to make more money (as was recently discovered with a different penny auction though not one connected with herps).
There were several issues with this particular group that a couple long threads both here and in the BOI cover extensively and are very informative.
Edit: Which Nikki has beat me too with the link. I would just add there was also an issue with a lack of proper permits for an online gambling/auction site and questionable terms in their TOS such as the right to not ship the snake to the winner without also giving a refund to winner and all the bidders.
Others are upset with the idea that you have to pay to bid with such an auction format. IMHO, this is essentially gambling and should be viewed as such and not as a real auction. There is also a concern about people buying their animals this way but I don't really see the moral/ethical difference between regular auctions and penny auctions when using live pet animals. I'm not really a fan of either one for quality breeding animals but regular auctions are probably fine for pets (with possible rare exceptions for breeders). I think the community's reception may have been different if a well established and respected breeder had initiated this but then again maybe not.