The premise of our advertising auction system is simple:

Publishers place their ad spot inventory for sale on the exchange.

Advertisers specify their targetting, and the amount they are willing to pay when such an opportunity arises. This is their bid.

When a viewer lands on a web page, a real-time auction is run among all the interested advertisers. The highest bidders win, and we display their ads.

Sensible defaults mean that new users can get good results simply by deciding on the zones they would like to target, and their CPM bid amount.

In our system, bids in general consist of 2 parts - the bid itself, and the targetting. This can be illustrated below:

This bid can be read as: advertiser bids up to $1.00 per thousand impressions, for up to 50% of the impressions in the sgForums ad zone.