Good for volume sites, not for premium ones
If you have high-volume arbitrage or download traffic, the popunder rates are honestly hard to beat and the fill is rock solid. But if you care about a clean reader experience the intrusiveness of the formats is a real tradeoff. I run it on one site and deliberately keep it off my main brand. Genuinely torn.
Strong rates and fill for high-volume traffic
Ad formats are intrusive for premium/brand sites