Link rating for PopAds

I really like PopAds because it's a high-quality source of traffic. Very easy to use and also they can predict how many impressions you'll have based on your bid which is great if you want to know how much you'll spend.

Also, They have categories that are great if you want to niche down your audience.

The only thing I see as a problem is the lack of traffic from most countries. Most of their traffic is concentrated in just a few countries.