This likely sucks for artists if you think about it a little bit.
1. Assume the artists are touring with sold out shows, or at least pretty good numbers.
2. "Exposure" here is primarily going to improve album sales, not tour attendance, simply because there's more room for album sales to go up than tour attendance. This is of course giving the NFL credit as one of the few organization whose offer of "exposure" over money might actually be worth something.
3. The artist then would be giving up a percentage of the revenue that they keep a very high percentage of (tour revenue) for an increase in the revenue that they keep a very low percentage of (recorded music sales). There are of course specific numbers that could make it work, but it sounds like a shit deal most likely.
Of course, the label would love it, because it turns revenue they don't get a cut of into revenue they get a cut of. If you think labels still have the power to force that down an artist's throat though, then I have some pets.com stock to sell you, because it's apparently 1999.