I have no experience of display and no real evidence to suggest this is a viable combination but was going to give it go. Pops seem to be all the rage right now and I've run them and can see the path to making them profitable but for various reasons, learning display fits far better with my longer term goals than learning more about pops.
A couple of people have suggested to me that that sweeps/display combo might not be the best idea. Any words of wisdom about why? Or anyone care to disagree with that?
The reason it might not be the best idea is because of compliance rules that don't like the offers. These rules change pretty often though, so maybe in 6-12 months, the situation is different.
Another reason that display might not be a great idea is because display inventory is very popular with brands as well. That means that you compete with high budget agencies that don't care about performance, while you have a small cut of a small payout offer and a much more limited budget.
I know of a few affiliates that ran display sweeps successfully, and I myself started on display with apps. Now, I don't know anyone who uses mainstream display as their main traffic type.
Unfortunately, I have similar experience to what Manu described above, after doing very well on mobile display, I had to pause majority of my campaigns there.