Stumbleupon vs. Digg

I've come across two websites that I am very interested in. Those two websites are Stumbleupon.com and Digg.com. Both are search engines that are primarily used as a form of entertainment. I am interested in exploring how these websites are alike and different as well as how they are changing the way that we use search engines. Instead of finding out information, are search engines now turning out to be used mostly for entertainment? Is Stumbleupon better than Digg, or vice versa? These are just a few of the questions that I hope I will be able to answer in my research paper. I expect my ideal audience to be the students in my class, as well as people who are interested in how search engines are being utilized by people on the Internet.