PFF tries to prop itself up with these extra products to put itself above all the other stat companies out there, and therefore make more money.
I think it's a business plan that's rooted in dishonesty, since they're not trying to take the subjectivity out of the analysis, like an honest analyst/stat guru would. It's not like it's against the law, they're just capitalizing on the huge football market that's out there.
But that makes me think they would also capitalize on any players/agents that want to pay to be a "priority PFF client." It's not a ridiculous notion, given their reputation.