On Windows Phone, mobile ad revenue is driven by the number of ads shown (“ad impressions”) and number of ads acted upon (“clicks”), as well as availability of ads to be served into the app at any given time (“fill rate”). Ultimately app developers are paid a certain “eCPM” (cost per mille, or thousand) for ads shown within their apps. To drive revenue, you want to create experiences that will add value to your customers while also driving ad impressions that garner the highest eCPM possible.
How do you do that? My first recommendation is an obvious one: create apps that are interesting and that drive engagement with lots of people. The more time customers spend in your app, the more ad impressions that are generated and the greater opportunity to solicit clicks. By appealing to a broad audience, I’ve tried to make my own apps as “sticky” as possible.
In-app advertising is not the only option open to developers, but it's certainly easier to implement than some of the alternatives, such as the freemium model, in-app purchasing, or relying on the app to sell subscriptions, merchandise or other services. Coding a good in-app system needs careful thought and a bit of trial and error, and this is a great article to give you a starting point.
You can read the rest of Zamora's advice over on the blog post.