The numbers that Google's Keyword Tool churns out can lead many on a wild goose chase

Is Google’s Keyword Tool Accurate?

I hear and read a great deal about people who use Google’s Keyword Tool to define the words and phrases they will pursue, finally rank for them, and see only a dribble of traffic. But it is like any other tool – you have to know how to use it so you don’t end up slaving away to optimise for something that will do you no good at all. So what do you need to know?