Depends on what you pay for. The Ancestry angle can identify the geographical areas where your ancestors came from, but you can get a lot more specific than that. These days, you can get an idea of the kinds of diseases you are most susceptible to. Breast cancer, for example, often has specific markers and I can understand why some people would want to know that.
Question is, do you want to know the detail? I for one don't; life is for living, not worrying... although I have a pretty good map of what happened to my ancestors for about 5 generations and its pretty good news.
The distant ancestry angle is more interesting though. I can trace my family back 12 generations with some accuracy and have "outliers" in the 10th century, but that's it. Genetic analysis can go back millennia, and I am considering that atm...
I've got a feeling I am related to god himself! That hunch is based on the fact that every morning when my wife rolls over and looks at me, the first thing she says is, "oh Jesus Christ!"

I'm pretty sure I've got a lot of lost brothers out there as well...