Read this article from Follow Me Internet Marketing.

“It is important that you know which keyword phrases to use as you begin creating and writing compelling ads for your Google Adwords campaign, so that people can easily find your ads. Perry Marshall (a Google Adwords expert) teaches pay-per-click users and advertisers to utilize the Google Adwords Keyword Selector Tool when creating their ads.

This free resource will allow users to uncover the best keywords in a niche, and may also assist in locating other related phrases for your campaigns, or in your keyword research. The Keyword Tool is especially helpful for fine-tuning your efforts when ads are performing poorly; if you’ve written an ad using low-traffic keywords, there is a good chance that your ads are not being clicked enough to make your ad effective.”