The BBC has an article about Americans looking for their roots through their DNA. There is some criticism of how African Ancestry interprets their results. I used African DNA for my tests because African Ancestry was a bit expensive ($349).
The criticism of African Ancestry is not unwarranted. What I liked about African DNA was that they were very clear to state that maternal DNA CANNOT conclusively link you back to a tribe in Africa for several reasons. Chief among these reasons is that the database that your DNA is compared to comes from people who are "known" to be--or say they are--of a particular tribe or region that are living. It's simply not conclusive.
This is not to say that the information is not useful. It can give you some ideas, confirm some leads and even offer new leads. DNA doesn't stand alone, but it can be combined with thoughtful genealogical analysis to draw conclusions about ancestry.
I was particularly offended by the quote from Mr. Ofori Anor, Asante magazine editor, "African Americans just want to be able to say they were once kings and once ruled the world." That is simply not true. What African-Americans want is what was TAKEN from us: our history, our heritage and our culture. We want connections to understand how we came to be here. We want a better understanding of what our ancestors believed and what gave them the strength to survive the holocaust that was American slavery. It's a shame that Mr. Anor fails to grasp the power of knowing your roots.
Found via the The Genetic Genealogist