Failing isn't that exciting, but a short compilation of someones failed attempts before nailing a trick for the first time could be good, but it would have to be edited very quickly to avoid the tedium of accelerating.
I actually think it would be good to see videos of people barely succeeding with a trick, and everyones flukes. I remember once wishing i had a camera on me, tried to whip a diabolo out of a friends two diabolo pattern, as i did it i managed to whip both, then do a sun, if i was expecting it to happen i could have kept it going. I always wished i had that on video. I also managed to do an excalibur genocide so badly that i managed to completely turn it horizontal again, and get it into infinite suicides.... It would be nice to see everyones flukes, but i think they rarely happen on video.