I also know this to be the case down here in Florida with the Southern Sprint Car series. The tracks don't pay them a sanction fee, they just pay the purse.
And I think all the streaming hoopla would die down if they were tape delayed- give folks a reason to go to the track. Streaming is changing business models everywhere. Look at Spotify. It's a great way to get in front of an audience, but you make squat. Same with digital downloads. Racing just has to adapt.