This is football ratings. I've poured over the numbers for years. We're talking about the SEC. If this was the Big East, MWC, C-USA, MAC, etc... Oklahoma would be the better addition simply because those conferences have a need for a top football "brand". The SEC has all the football brands it can sustain at this point, basically you can only diminish one brand in place of another. So, if Oklahoma was to join that would only damage the Arkansas, LSU, A&M, or Oklahoma brand. It doesn't take a rocket scientist to figure out you can't take the top teams from the Southwest, SEC, and Big 8 and throw them in a conference together and expect all the teams accustomed to being in the top 3 of their conference to remain that way. It's simple math. I've seen times people here heavily disparaged Arkansas, and even A&M and that is because both suffered from a powerful conference that pushed them below their traditional levels. They are historically top 20 teams, but when two of them play each other, one still has to lose.
I've looked up numbers, and North Carolina's tier 3 revenue exceeds Alabama's, and of the disclosed schools was #1. Tier three is what would become SEC Network content. The trick is that basketball has more tier three games, so if you are as high profile as North Carolina's basketball program you offer up a lot of great network content. On top of that, they are in a much larger state, so they can bring in much more in subscriber revenue. Basically, they would be the best content provider and additionally they would bring in one of the largest subscriber bases.
That leads into CullmanTide's point. The SEC could benefit from a basketball brand without upsetting anything. They are lacking in national basketball brands and UNC would really drive up interest. This means when it comes time to negotiate broadcast and cable deals they would still be adding because not only do they bring in a larger regional footprint, but they make the SEC basketball games more valuable. So, when you add it all together it isn't just that North Carolina is more valuable to a network, it's that they are much more valuable to the SEC. The truth is for the existing SEC programs, Oklahoma could be a net drain. They could damage existing football brands, and drain football talent. North Carolina? There are plenty of recruits, they are highly unlikely to damage existing brands, they would help the network, broadcast deals, etc...
Notre Dame is a different equation (and even more unrealistic), because of a few factors. They are one of the few football powers out there that I think could actually improve the SEC's welfare. Otherwise, basketball schools are the way to go. Can you imagine the lunacy of a playoff with automatic entrants from four super-conferences and the SEC having half of the top programs? The other conferences would be giggling their way to a playoff, and the SEC would be happy it was automatic at all or else their brutal schedule might create a mess of 3 and 4 loss teams.
So what's Louisville doing that Kentucky is not? $40M vs. $18M. Same state to boot. No one else in the country comes close.
I believe the Big East only shares football revenue. So, Louisville was running an elite basketball program with 0 revenue sharing. North Carolina and Kentucky have to share everything but tier 3. It's just a reminder that yes, the elite level basketball schools do generate a reasonable amount of revenue.