Because BookBub Ads are served through an auction, the cost of running ads depends on the details of each particular campaign and the other advertisers competing in the auction at any given time. Advertisers set their own budget and bid for each BookBub Ads campaign. The budget determines how much they want to spend overall on the campaign and the bid sets the maximum rate they are willing to pay to reach readers in their target audience.
There are two ways to bid on BookBub Ads: cost-per-thousand impressions (CPM, where one opened email = one impression) or cost-per-click (CPC). At the moment a reader opens an email or a page on our website, our auction identifies every ad targeting that particular reader, determines which has the highest bid, and then displays the winning ad for that reader. If your ad has the winning bid, you will pay the rate of the second-highest bid for that reader.
This means the amount you pay for each ad impression or click 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.
Additionally, we will never charge you more than your maximum overall budget. This means the total amount you spend on BookBub Ads is entirely up to you! You can run a campaign with a budget of just $10 or over $1,000.
You can learn more about how the BookBub Ads auction model works here.