Regarding TV markets, it's about local cable TV. That's where the Yankee advantage is--in their local cable network. they have the biggest--bigger than NESN, the Red Sox network. Teams don't share in these revenues. Plus, in MLB, the visiting team only gets about 10-20% of the ticket revenue, vs 40% in the NFL.
In LA, the Angels just signed a big local cable contract, and they had to sign Pujols to get their low cable ratings up. Signing Pujols was a must for their TV contract. That's why they made him an offer only a fool could refuse.