The interesting thing is that these key words are seldom the ones that the search engines will proclaim will get you noticed. The ones they want you to use - or rather, recommend you should use - they're also recommending to every other Johnnie on the Net. And if everyone is using the same bunch of key words, guess who's going to get noticed? Not the little bloke with a few articles floating around. HitTail's approach is to give results based on the words that are already in your blog/article/whatever and tell you which of those are making an impact. I find it effective, certainly effective enough for my particular neck of the woods.
