Entrecard - does it really help?

I heard a lot about Entrecard helping bloggers and site owners increase traffic on their sites. I have been seeing this EC widget in almost every blog that i visit but only recently that I decided to give it a try. Honestly, it is not helping me much to raise my real rank. I only get very few drops in my site, even if i did lots of drops on various blogs. Probably, i still need a lot to learn on how this thing works. I'm sure i am missing something.