A “pop-under” ad is not a new format, it´s been around for as long as the rest of the formats out there, just not being put to great use and the reality is, pop-unders can make you more money with the same mobile traffic you´ve been monetizing until now.
With the same exact clicks you are using on banners, redirect etc. you can execute a pop-under that is statistically proven to generate a higher CPM than other formats. A simple ad that is delivered “behind” the initial browser product, it doesn’t bother the user, it doesn´t take attention away from the original banners on the browser and it´s not intrusive. Pop-unders are only visible once the user is done with the current page and closes it.
To assure this “non-intrusive” behaviour, pop-unders work on several “controlled methods”. For example, frequency capping, a pop-under ad is only delivered to a user every 24 hrs. Another method that helps is that the pop-under is not generated on the initial/primary page, it will be generated once the user is within the site. This will limit the number of ads that “pop” per user. All leading to a less aggressive user experience, however, generating extra revenue for you each time.
Basically, the correct use of a pop-under ad leads to is more revenue on top of your current benefit, without you having to generate more traffic. It´s the most simple and cost efficient optimisation in the current market