I've found that their rates can be decent for high-traffic sites in tier 1 countries, but the real issue is the lack of transparency in their reporting. I've seen discrepancies of up to 20% between their reported earnings and actual payouts. Adsterra, on the other hand, has been a better option for me, with higher CPMs and more reliable tracking, but their spammy banners can be a turn-off for some users. To maximize earnings, I've started using a combination of Adsterra and Admaven, with a focus on native ads and push notifications, which have yielded an average CPM increase of 35% over the past quarter.