I am just interested in knowing that percentage of developers excel at competitive programming. Also interested in the reverse statistic which is about how well competitive programmers perform in a real programming scenario. At my company, I only know of two people who are "Yellow" rated on Topcoder.
I can't say I have ever heard anyone bring up Topcoder in a professional environment. If you are interested in it, then by all means, compete. But don't think it's going to help you make any extra money in life.