Ad Networks and Inventory

Beyond the big self-attributing platforms, app ads also run across thousands of smaller ad networks and in-app ad space reached through mediation inside other apps and games, which is where a lot of cheap install volume comes from.

You start on the giants, then you go hunting for scale and stumble into the wider market. This is a long tail of smaller networks plugging into ad slots inside other people's apps and games, stitched together by mediation layers that auction each impression to whoever bids. It is a real place to find volume, and the cost per install can look wonderful next to what you pay the majors, which is exactly what makes it tempting to pour more budget in.

You need to know why some of that traffic is so cheap. This corner is where install fraud concentrates, because the further you get from a transparent partner, the easier it is to hide. You run into bots that fake app opens, click injection that fires a click the instant a real download starts to steal the credit, click spamming that floods your measurement partner with junk taps hoping one sticks, and device farms running racks of phones to manufacture installs at scale.

Treat a suspiciously low cost per install as a warning, not a win. Cheap installs from networks that will not show you where the traffic comes from are often worthless or outright fake, so they demand fraud protection and hard vetting before you scale them.

If a source will not show you its traffic, that silence is your answer.