I love Mayer (at least when he is on his game, he shits the bed for at least 2 songs every album but hey it gets him paid) and I thought about him but then I thought about this scenario.
Say 15 years from now there are two 12 year olds learning how to play guitar. Both have amazing potential. Both are completely and totally in love with music to the extent that they will not rest until they "make it". The difference is that one idolizes and is learning by mimicing Jack White while the other is doing the same with John Mayer....
I put more faith in the Jack White fan to make a significant impact than I do his John Mayer counterpart.