Wordtracker is good, but it's incomplete. There is a lot - a LOT more data in the Google database. It's all there. You may get 0 searches using wordtracker for a lot of terms that actually do have significant search popularity from a domainer's point of view.
Currently I cross-check between Google and Wordtracker. Like Mark said, Google also gives popularity to some phrases that make little sense. It could be that people type those in by accident, or something else.
Google's tool also is not reliable. Sometimes it gives "insufficient data", the next day, "10,000". Their database is probably something to dominate the Universe with, but the tool itself is buggy.
Also there is a discrepancy between the High CPC bids and advertiser competition. I know they are not the same thing, but to me it seems like the discrepancy is too big.
Also there are discrepancies when you compare their "advertiser competition" and "high cpc bid" and then the actual number of ads that appear in Google searches. I tend to trust the number and quality of the actual ads for domaining/SEO purposes. I wouldn't trust the tool too much. When checking the ads, use this format:
http://www.google.com/search?adtest=on&hl=en&gl=US&q="your term"
Change the gl=US to whatever country and hl=en to whatever language you wish to check for.
To me that's the best way to evaluate a search term's desirability and advertiser competition at a glance.
I'm currently experimenting a lot with the new Google tool. You can check the available domain names board for my thread, which has examples of search term numbers and available domain names found using the Google tool.
Again like Mark said, Google rules the search world, and they are Gods when it comes to search data. To me it seems we are incredibly lucky to have this resource, especially from a company that generally is not webmaster friendly.
I consider the Google search tool by far the best tool that is out there. It's also extremely smart when researching related terms and long-tail terms. Google have their semantics together better than anyone out there.
I have a lot of thoughts on this matter, I'm doing a lot of research right now and will post a follow up once I reach some definitive conclusions.
Oh yes, whoever said that the Google data is not just search popularity but something to do with how often ads are appearing, I think this is incorrect: to the best of my knowledge, this is genuine search popularity data, it's probably the closest you will ever know to how many times a given search term is actually typed in to the google search box each month.
I emphasize that these are just my opinions based on my personal research, so I could be wrong though I think I'm right
Also, with the Google tool I've found it's easy to find search terms with high KEI (keyword effectiveness index) - those are great for SEO.
Oh yes, whoever said that the Google data is not just search popularity but something to do with how often ads are appearing, I think this is incorrect: to the best of my knowledge, this is genuine search popularity data, it's probably the closest you will ever know to how many times a given search term is actually typed in to the google search box each month.
I emphasize that these are just my opinions based on my personal research, so I could be wrong though I think I'm right
