check this post out http://www.sjlwebdesign.co.uk/sjl-blog/index.php/internet-marketing/koi-keyword-opportunity-index/ It explains a technique to selecting the best keywords from the popularity and competition. Its really good!
That is interesting, but how do you really take advantage of it? Using that formula, I have sites at the top for a KOI of over 2,130 and problems with other sites with a KOI of around 12. Hmm, I wonder if this is really that useful...
Here is how I select keywords and it has worked for me. I look closely at the number of competing sites. The KOI is flawed because if the competing sites is too high you will never get traffic even though the monthly search volume is high. I look at the keywords that are currently sending me traffic and determine how many competing sites they have. This gives me an idea of how competitive my website is. Now I select keywords in that competition level. Let's say that I get traffic from 20 keyword phrases. I analyze these and find out that the average number of competing sites is 600,000 for these 20 keyword phrases. I now know that I can compete with any keyword phrase with 600,000 competing sites or less. It's just a guide and not a hard and fast rule. Make sense?
choose keywords that have a mid level search rate so that you dont get dominated but the biggest keywords