Every bid you place is in CPD, which stands for "cost per day". A bid of $1 CPD means you're willing to pay $1 a day to have your ad displayed. Pretty simple, right? You can put time limits on your bid too: a bid of $1 CPD for a week means that you're willing to pay $1 a day for one week of advertising - so the most this bid will end up costing you is $7: one dollar each day for seven days. What's most helpful is that CPD is a rate, not a set fee: a bid of $1 a day that only lasts for 3 hours would end up costing you at most about 12 cents, since it's for such a small fraction of a day!
Your ad is displayed only when you're the high bidder. Any time when you're not the high bidder, you're not charged a cent. But don't worry: your outbid bids remain active until they expire, and can still become the high bidder in the future, when any higher bids have expired. This lets you set long-term bids on sites that capitalize on dips and lulls in bidding. And to make things fair, all these charges are to the nearest second. There's never any surprises.
You can advertise for free! It's a great way to explore Project Wonderful. Unless a minimum bid has been set by the publisher, bidding starts at $0, which means free advertising for you! If your bid is at $0, and you're the high bidder, you won't pay a cent. And no matter what you've bid, if you're the only bidder, you'll still get free advertising until another bidder joins in!
You're not charged for clicks or displays - only for the time your ad is shown. This replaces the older CPC ("cost per click") advertising model, where advertisers are forced to pay for fraudlent clicks that don't get them any business.
And you're always getting the best deal. Like most auction sites, we use proxy bidding on your behalf. This means that if you can win the auction without bidding your maximum bid, you will. For example, if someone else has bid $1 and you've bid $5, your bid will only be increased to $1.10 to outbid them and become the high bidder. Your maximum bid is never revealed to others, and in case of a tie for high bidder, the earlier bid takes precedence.
We've set up a few examples showing more about bidding and a few auctions in action, so you can get a feel for how bidding works in real-world situations. Check it out!
About Project Wonderful:
How the Infinite Auction works:
Advertisers get the best deal.
Publishers make the most money.
See an Infinite Auction in action!