There's alot of bad talk about the AAF here, and while the comments about the poor game play are valid, that league was intended to be a testing ground for NFL rule changes & develop a minor league for upcoming NFL players.
The rules were unique though. No TV time outs & game in under 2.5 hours. Shorter play clock. No extra points, 2 point conversion mandatory. No kickoffs. Onside kicks replaced by a 4th & 12 play from your own 28 yard line. The biggest thing was that all players & the football had microchips with real-time tracking technology. That app could eventually allow the potential for real time sports betting for every play or series, but the league could never get it to work right. Sports Illustrated said the league was eventually purchased & immediately shut down, just to obtain the rights to that technology.
It's heart was in the right place though. It had the support of the NFL (former executives in charge, former NFL coaches, use of NFL practice squad players, games on CBS/TNT/NFL Network, etc). It just didn't have the financial backing of the NFL. When the league really started hemorrhaging cash, they pulled the plug fast. Can't really blame them.
The reason leagues like the USFL worked in the mid-80s was because they had deep pockets, had teams in big markets & signed the top players out of college (like Hershel Walker, Jim Kelly, Steve Young, Doug Flutie, etc), which gave the league immediate legitimacy & sparked interest. The games were fun & exciting. They had a good thing going & showed that a spring football league could be successful. But when they decided to compete directly against the NFL & play games their games in the fall, everything collapsed. It was a different time.
When your star players are NFL 3rd stringers & practice squad guys, a new league is never going to be successful. Too many other entertainment choices for people today than to sit there & watch bad football. XFL is going to suffer the same fate. If they were smart, they would sign Antonio Brown ASAP and make him the showcase of the league. Let him put up 2000 yards receiving & 20+ TDs. People would tune in to see that shitshow, that's for sure.