Excerpt from osk’s blog post, Adding ads to TETR.IO, six months later, I thought it was really useful so sharing here for IO Game devs
AdinPlay, like most partners, will sell your ads in many different schemes. This is generally not very visible to us publishers, so all we really get to know is a few key performance indicators (or KPIs): ad requests, impressions, clicks (and click rate), and RPM. An ad request is when your site (or in my case, the client) requests an ad, and an impression is counted when said ad is displayed on screen for at least a full second (we can say with certainty that the ad has been seen by the user). Then finally, if the user clicks the ad, we count that as a click.
The magic number here is the last: the RPM. RPM stands for Revenue per 1000 (usually impressions). It’s often also called CPM (cost per 1000). CPM is what the advertisers pay to advertise on your site, and RPM is what you receive as publisher. Your RPM is generally controlled by three things: the click-through rate (the percentage of impressions that lead to a click), the kind of content you publish, and the day of the year. Games also tend to not get super-high RPMs to begin with, compared to say, car rental sites or accountants.
Furthermore, your RPM will almost always start off low. After a few weeks, your RPMs will start normalizing to their normal levels. From then on, your RPM can mainly be changed by the time of year, and the type (and placement) of ads you serve. For example, things like Black Friday will see a spike in RPM, as there will be more advertisers competing for the same ad space. Simply put, advertisers are always bidding on ad spaces, and if there’s more competition, ad prices will go up. This also means your RPM will generally go up through the year slowly, go down at the start of every month and quarter (as ad campaigns tend to end at those times), and that January will be by far your worst month.