Really, if you haven't, you should! It is a great way to earn points that you can use toward all sorts of things, including gift cards to places like Amazon.com, Ding.com, etc...I have even used it to get PayPal cash! If you search for anything online, then try this! It is powered by Google and Ask.com, so you know you are getting good searches.
If you sign up under me, I get points from you. The same happens when you get friends to sign up under you too! So, try it out for yourself!