I think this would make it incredibly difficult to get a consensus on which ad would be shown, as well as finding sponsors to foot the bill. TV ads aren't cheap

The only consensus needed is from the person or group paying for the ad. (By the way, when you're the first response on a thread you don't need to quote the original post.)
Having ads on TV is a great idea! The challenge is find the person that's willing to spend tens of thousands of dollars to advertise bitcoin on TV for zero direct payback in revenue to them. We're not talking about advertising a business, we're talking about a currency and investment!
Any thoughts on how to solve that problem?
EDIT: I suppose mining operations would benefit the most from transactions, so they should be the entities with the greatest incentive to advertise on TV.