The big problem WWE will have in marketing all of WWE programming as a single package, then comparing its programming value to Nascar, NBA, etc is that those sports franchises are split up. Nascar is so expensive and runs so long through the year that no single network runs the entire season. Nascar is a good comparison as it has several different series of racing that it runs on TV as well.
The Sprint Cup is their equivalent to RAW. That's what brings in the big money and what FOX, etc want to put on their top station. But then there's the Nationwide series, which is a lot like Smackdown. Lesser known names generally, lower ratings, less interest. You rarely ever saw a Nationwide race on the main FOX station. I'm guessing they had it on the Speed Network.
I believe the NBA is also split up between TNT and ABC. The NFL splits up their leagues to maximize profits. Of course both the AFC and NFC games are equally alluring. They don't have a Smackdown or Main Event dog they're hoping to force on someone.
IF they do get someone to accept the entire package, I don't think they'll see NBA or Nascar level revenue from the networks.
If anything, if the WWE network is to launch around the same time they're looking to shop these shows around, it's to see if anyone is willing to pay stupid money before they bring all that home to their own network.