People Being So Self Absorbed

Don't you just hate it when you have certain people that are so self absorbed that they don't bother to help you out? I know of people like this on twitter. You selfishly give of your time to tweet something to help them out, yet they never rt your articles, blogs, etc. They will, however, rt anything that you've done concerning them. Why are people like this? They get enough views on their own, so what is hard about rt'ing something someone else has done? It is just aggravating and I had to vent. Sorry, I am usually a positive, upbeat person. I'm just un-polished.