That has changed and video ads becoming a thing has changed it even more. Banner ads back in the day were not something people could be forced to sit through and there was virtually no targeting. Now that they can target certain audiences and essentially force them to watch, ad dollars don't have to be spread so thin and therefore they are able to spend more for any specific ad slot. Realistically though, I think it's to just push people to the higher tiers. If people don't upgrade, then you're getting some ad money on the side, if people do upgrade then great. They view it as money "left on the table". If you're willing to spend one cent more than you currently are spending they view it as their job to capture that.