1. Demand/supply ratio. There were 289,000 searches for "fishing" last month, but could you compete against the 35,000,000 results on a Google search? "Bass fishing tips," with 3,700 searches, and 31,000 results is a more likely winner.

2. Total supply. For "dirtbagging," Google shows 240 results, and there may be 20 searches monthly for the term. It was easy to get on the first page of results. On the other hand, a keyword with a demand of a million, and a million search results has a better ratio, but can you really get in the first few pages of results? Whatever the ratio, you have to be able to compete against the supply. If you are on the tenth page of results, virtually nobody will find you.

3. Type of keyword. Getting good search engine placement is one thing, but what type of visitor are you getting? Who is more likely to buy something from you or click on your affiliate links, a searcher for "fishing stories," or "fishing poles." If I was selling gear, I think I'd be happier with half as much traffic for the second term as the first.

4. "Odd" keywords. I optimized my site www.IncreaseBrainpower.com for "brain power," and later found there was even more traffic for "brainpower." Both, by the way, are in the dictionary. Look for odd search phrases, but be careful optimizing for misspellings and bad-grammar keywords, if it might hurt the reputation of your site.

5. Value of keyword ads. If you rely partly on Google Adsense for revenue, you may want to consider the ads that will be diplayed for a given keyword. Poetry pages will get you about $0.04 per click, while surveilance cameras can get you $2.00 per click.

A final consideration when doing keyword research is to consider your interest in the topic represented by the keyword. Do you want to write a page on that, and can you deliver what a searcher of that term is looking for?