I think most people realize this after a few days of using these free BTC sites. I know I did myself. It's hard to grasp how small a micro bitcoin is until you realize that these sites don't give you 1/10th of that.

The goal is to get people interested in bitcoin, and find alternative ways to get them. I know it piqued my interest when I saw some of these sites. Besides, if they gave out more, they'd go broke pretty quick, as we found out with BitCrate.