I ran across this video from Erica Douglass of Erica.biz. It's a neat little video tutorial on how to find profitable keywords to use for blog posts that get free Google search engine traffic to your site. It's pretty nifty.
How to Find Profitable Keywords
I like how she spells everything out. It's really all about finding longtail keywords that don't have a lot of competition but that do have a good number of searches per month. The key is finding those keyword phrases that people use when they're in a buying frame of mind. That is to say, this is a method on how to find profitable keywords that people use when they're searching for solutions to problems.
The video below explains it all.