Monetizing your site with push notifications
But you need massive traffic to get enough numbers, so it's not really the main monetization strategy. In saying that, if you can buy some very cheap traffic (proxy traffic) and run the ads then you may break even when combined with Adsense and a front-end global CPA offer - worth looking into? Just need to get enough traffic to break even in the short-term before it starts becoming profitable. The RPM from three sources should be enough to cover the traffic after doing some quick math on it.
Pros: High CTR
High opt in rate
Can make money even when the visitor has left your site
Cons: Low CPC.
USA traffic is only 0.046 per click on average.
Looks spammy