The Perfect Audience bidder is the tool that places bids during real-time bidding auctions on your behalf. When you create a campaign, you tell our system which Retargeting Audience to search for across Facebook or the web, and our bidder seeks out places where someone with that cookie in their browser is about to load an ad. An auction happens in a few dozen milliseconds where our bidder and the bidders of many other companies place bids for the ad impression based on their campaign instructions.
Example: For instance, in one auction there might be three bidders. One bidder, with a big brand campaign from an ad agency might be set to bid a flat $3 CPM for any impressions generated by people on a specific cookie list. Another bidder, from Perfect Audience, might be set to start at 0.01 CPM for the first bid, but to keep raising the bid if needed up to $5 CPM or until it wins the auction. A third bidder from a direct respond marketer might be told to bid a flat $0.25 CPM for the impressions.
What would happen: The three bidders would all place their bids, $3, $0.01, and $0.25 CPM. The $0.25 bidder would lose immediately since it's not programmed to go any higher. The $0.01 Perfect Audience bidder would place a second bid and outbid the $3 bid by one cent. The $3 bid would concede because it's been told not to raise its bid. So the second bidder, with the $5 cap would win the impression at $3.01 CPM.
Our tool keeps bidding higher and higher until it wins by one cent or it hits a ceiling set by the advertiser with their maximum bid setting in their campaign form.
For this reason, if you set a max bid, you will lose out on some hotly contested impressions. Those impressions might be valuable to you or not, it's up to you to test rigorously and find out what works best for your marketing.