List Building: best practices?

[Daniel Elbe]

Greetings!  New investor in the Colorado Springs area.  I've identified the neighborhoods I'm interested in farming, and started building my mailing list.  Through a combination of walking my dog through my target neighborhoods to identify distressed/vacant homes, and combing through the pre-foreclosure list for homes that meet my investment strategy, I've got a pretty meager list.  Leaning on people with experience (especially in Colorado!), do you recommend buying mailing lists?  Where is a good place to start?  I'm skeptical on the quality of lists someone else may provide, but I also don't want to spend all my time finding homes to mail to!