The "relatively high" salaries also mean that 20 minutes of ads in a 60 minute session "costs" more. It's not quite as simple as applying my hourly rate to the ads, but it's at least a decent place to start the analysis, and by that metric it doesn't take long before the ads are the dominant cost of the service. It gives me a lot of virtual money to deploy to the task of turning to entertainment that doesn't annoying vast quantities of my time to squeeze out fractions of a penny from me because they can do it in bulk.