will eventually define your value. The retweet, the +1, the likes and re-shares are all adding up and building a social brand of you.
If you are doing it because someone asked you, or even worse just for the heck of it, think again. You might end up being a noise generator, and like you, no ones likes noise.
Side Note: Remember, today you have a chance to build value, not just to the ecosystem you are in, but to yourself as well (which wasn’t this easy about a few years back).