Advertisers set their own budget and bid for each ad campaign. You can bid for impressions through CPM bidding (where one opened email = one impression) or for clicks through CPC bidding. If you are the highest bidder for the audience you’re targeting, you will win impressions. For both CPM and CPC bidding, instead of paying your maximum bid, you will only ever pay one cent more than the next highest bid in the auction at the moment your ad is served.
For example, imagine a scenario where three campaigns are targeting the same readers today:
Campaign 1: $6.00 bid
Campaign 2: $5.00 bid
Campaign 3: $4.00 bid
In this example, Advertiser 1 would win the impressions at a $5.01 CPM (one cent more than the second-highest bid). Now imagine that Advertiser 2 finished serving today, leaving Advertiser 1 and Advertiser 3 competing for impressions tomorrow. Advertiser 1 would still win, but that advertiser would now be paying a $4.01 CPM (one cent more than the new second-highest bid). Your campaign results will show the average CPM or CPC you paid throughout your campaign.
The amount you spend on BookBub Ads is entirely up to you! You can run a $10 campaign or a $10,000+ campaign (or anything in between). We will never charge you more than your maximum budget. The amount you pay for each ad impression or click, however, will depend on factors like the targeting you select and the bids other advertisers submit for the same audience at the same time. Because of this, the cost for an individual impression or click will always be variable, though you will never pay more than the maximum CPM or CPC you bid when you set up your campaign.
You can learn more about how the auction model works here.