Promoting other people actually helps promote you in the process.
It’s paradoxical, but it’s not really that hard to grasp: The more you promote people/ideas/etc. (and the more you become known for promoting good people/ideas/etc.), the more likely it is people will keep coming back to you for the latest insight on what they need to know. Jay Rosen explains this (essentially) probably better than anyone in his (now famous?) “Ethic of the Link” speech:
It’s just like real life: No one wants to listen to a guy talk about how awesome he thinks he is. People are out looking to help themselves (they need a job, want to learn to code, etc.) and if you point them to helpful information, they’re likely to remember you and come back. That—the return trip—is when you come into the equation and make a connection with someone else who may be able to help you.