Never played professionally, but my big fps days were a little before that stuff took off.
Was officially (as well as unofficially but obviously..for a lot longer) the best player of Rogue Spear (incredibly similar sequel to the original Rainbow Six, with diff maps). Was the leader of easily the best clan in the game, blah blah. Played that game WAY too much for about 3 yrs straight, like 8+ hrs a day. Was very, very good...I was on a whole different level, due to the twitch and reaction times involved. It's also the main reason I dropped out of college the first time (later returned and got my degree).
I did have somewhat of an opportunity to write a guidebook to the game, but all that really amounted to was a few emails between myself and Microsoft, basically saying they were considering adding an online guide and wanted me to write it, but were still unsure whether they wanted one or not. As it turned out, they opted not to do one, said they didn't need it. This was back before the days of professional gaming, huge gaming clans, etc. Different times.
It's just one of those things. None of my RL friends knew much more than that I played it, let alone how good I was. Never got paid for it or received any recognition like some of the so-called "elite" gamers do nowadays. I've more or less stayed away from FPS since then..limiting myself to playing at friends' places, etc. I know deep down that I could be incredibly good at most FPS titles, but I wouldn't want to spend the 2+ years ramping up to it. I had my time, and for the most part don't regret it. I can say I was without a doubt the best in the world at something (albeit with only around 7k players and in a video game of all things), but that's enough for me. Good memories.