[mrguyorama]

Indeed there are groups and "businesses" that "pay" you to install apps. I assume someone is on the other side of that transaction paying for new user installs. Doing it yourself would probably be cheaper and you would probably be offering a much higher payout than those systems.

[for_i_in_range]

It's called "incent traffic" and it's notoriously awful traffic. Users are worth 5% of a normal user because they're freebie seekers who are usually broke.