I use Twitter and don't have very many followers but will admit, they are in my areas of interest. Also, I use Twitthis to share something I'm reading that maybe others might be interested in. I get about 3-5 followers a week and some are good while others are totally unrelated. Also, being a writer online, having my site url in my profile helps me get new followers plus all the tweets show up on linkdin, FB and my other social sites.
if you want to be noticed, Twitter is a good platform.