The Google AdWords keyword tool external is recommended by a lot of e-books to use for keyword research. Not many people know the difference between this and the regular AdWords keyword research tool. Even though they are very similar, they are definitely not the same in usage and results.
First of all, for the AdWords keyword research tool you need to set up a free account where you need to enter all your data, address, etc. which takes a little bit of time and may be inconvenient, but it is worth setting it up, as it has several benefits.
First of all, in order to use the google.com external keyword tool, you need to enter captcha, several times, which many people consider annoying. The keyword selector tool inside the Google AdWords account does not have this. Once you are logged in, you can do as many searches as you want to.
But there is a lot more important factor also; the Google AdWords external keyword selection tool only gives you 100 results. This means when you enter a keyword, it cuts off a lot of the results. If you are looking for long-tail keywords for article marketing, the best keywords do not even show up on the search results. If you filter out the high search volume phrases, your get something.
If you use the keyword selection tool inside your AdWords account, it gives you 800 search results, which is a lot better.
Unfortunately neither of these tools is very good for SEO, as they do not show SEO-type competition only PPC, and the number of searches per month do not strictly indicate search text entered by users.
Do not forget though that these keyword tools change over time as they get updated with new features.