Most of them are botnets. Luminati, geosurf etc are all botnets. For example, luminati claims that people willingly download their hola app, but come to find out some MIT guys did some digging and found that 30% of their network was comprised of IoT devices. Also, most of the same IP's found on luminati are also found on other botnets, such as geosurf. So the reality is that these companies are paying people to get installs (ppi campaigns) and these guys are loading up all these paying botnets into the same installer file.
Also, come to find out only about 4mil ip's are on luminati - not 30+mil