I can see the gambling aspect in that it would be similar to playing slots.
Every bid is like hitting the button on a penny slot machine. In hopes of a payout.
If you also look, there is an auction on a MacBook that includes 5,000 bids for the winner. So the idea is to keep people bidding more and more. An addiction if you will.
There are other sites just like this one. One is advertised on cable on a regular basis. Doing a google search will bring up hundreds of links to how this works. It is legal but the bottom line is the owner can offer a $40k auto for penny bids. Participants have to purchase 'bids' at a huge cost say $75 for 100 bids (NOT 7500 bids - penny each). Owner gets 1000 people to purchase the $75 package, which is a very conservative number and you've got the cash to cover the vehicle cost. The entire bid process eats up approximately 50k bids over a 24 hour period and people will exhaust the bid supply and replinish by purchasing additional packages $75+ per.
Bid can be automatically placed in your absence and also exhaust your bid supply. Only person getting rich or something out of this is the owner.
I heard about Beezid.com on Howard Stern and tried it out, same type of site. If you get lucky at a $1 a bid you can win stuff pretty cheap. I read the final results on most auctions and it pretty ridiculous how much money the site makes per auction. Say a $500 American Express card goes for $45, the auction goes up a penny each bid and started at a penny and each bid costs $.75 to $1, do the math. I was curios, spent $40 or so for a "bid pack" and after 5 minutes lost patience and still have 30 or so bids left.