Users aren't paid for watching, they are paid for the browser loading the advertisements. I promise you that the moment this becomes even remotely profitable, p

Users aren't paid for watching, they are paid for the browser loading the advertisements. I promise you that the moment this becomes even remotely profitable, people will be running VPSes with automated browsers (or multiple local instances rendering to a virtual frame buffer, with mice/keyboards simulated to generate clicks). There is no way around this kind of automation, except perhaps given some pretty invasive rootkitting done my the browser (and that still doesn't mitigate the virtualisation problem). Given that these things are possible or even pretty easy to do, it is an inescapable fact that this model will fail.