Yeah man, for mostly Tier 1 organic traffic, getting $0.5 to $0.7 CPM on popunders is honestly pretty low, even for a random weekday like Tuesday.
Popunder rates are never amazing, but with US/UK visitors hitting your site from Google, you should be pulling at least around $1.50+, sometimes even double that if your traffic’s clean.
Feels like Monetag isn’t valuing your traffic properly. Either they’re reselling it through a chain of brokers (which eats into your CPM), or the ads they’re showing just suck bad landers, low bids, etc. Could also be you’re showing too many pops per session and it’s killing quality.
If I were you, I’d start testing other networks even just rotating them daily and tracking CPM yourself. Propeller, Adsterra, PopCash give them a shot and see who pays better for your crowd. Also maybe try mixing in other formats like push or interstitials. Sometimes they quietly outperform pop.
Bottom line: if your traffic is real and mostly Tier 1, you should be making more. Don’t settle, try some alternatives and see who actually respects your traffic.