I have an uncle that invest in these properties. Although, he gets the worst of the worse.
I have been to a few seminars(Rich Dad, Poor Dad), where they say it can be quite profitable getting property that needs a little work.
I am not saying it is easy, you just have to be on your feet and looking at all times.
Say you get a house at 20K below market value, do a little work. Maybe put 5-8K into it, and there is a profit of 10K.
I guess the better term, would be "flipping" the property.