Fill out the online survey(steam://takesurvey/2/). You need Steam for the survey. Since part of the survey is about hardware, you should use the computer you play on to fill out the survey.
Apply to win a key on our site. The more people you refer to here and the more people you have asking valve to give us keys to give away to higher your chances are of getting one from CSGODev.com
NOTE: You will risk your entire steam account being banned, closed, or disabled if you are found selling a key, or letting other people play on your account.