Right now, the only people who use nicknames are gangsters, boxers, and mixed martial artists. For the latter, it seems to be a requirement. Everyone on the Ultimate Fighting Championship seems to require a nickname so that Ultimate Ring Announcer Bruce Buffer can drag out his name during the introductions: "Randeeeeeee 'the Naaaaaatural' Coutuuuuuuuuuuure."
Back at WFC 2005 (that's not World Fighting Championship but World Fantasy Convention), new writer Diana Rowland was lamenting the fact that there were already several Diana Rowlands who were more famous than she was.
I suggested that she add a boxer-type nickname, and become Diana "the Bomber" Rowland. I called her "Bomber" for the whole convention. I have to say that she took it well (but there's no mention of "the Bomber" on her web site).
It's clear that writers need some damn edge when it comes to clawing their way through the marketplace, and colorful nicknames are at least low-cost.
Would I be more famous if I were Walter "the Whirlwind" Williams? Would Heinlein have achieved greater fame if he were Robert "Squarehead Bob" Heinlein? Would "Honest Dan'l" Abraham make an impact on the marketplace?
Or do you think it wouldn't work without Bruce Buffer to make the introductions?