Cancel three shows, two of which are doing very well in their time slots, add some wrestling elements and top it off with a horrible marketing - this is the XFL.
NBC dropped the ball horribly on their attempt at "new football." Their first mistake was trying to mix the two. Football fans aren't always wrestling fans. Then giving the guys a dangerous job in which they are working for tips (cash given only to the winning team) makes you wonder who's pocket all that extra cash went in? The middle class isn't going to watch men who have to play to put food on the table, that's not right. And if a guy got hurt, well that's too bad. The only thing they had going for them was the scantly clad cheerleaders, oh wait they already have that in the NFL.
Ultimately, NBC made a huge mistake by cancelling three shows on Saturday night to make room for this detritus. The Others, Profiler and The Pretender were higher quality shows that brought in audiences on a night where hardly anyone watched. Because of this poor decision, NBC lost: lots and lots of money, three good shows, their ratings hold on Saturday nights and the respect any fan of those three shows had for NBC.