Hi Michael, I'm Mal, and I work for Wordtracker Customer Support. I just wanted to put my 2p'th into your question, as comparison between these tools comes up alot. The two tools are very different beasts, and it's fairly commonly accepted that the Google tool is much more geared towards PPC than SEO - and Google doesn't seem to make a secret of that. With up to 1000 results for each seed, Wordtracker offers access to the longer tail of search, and the list management tools available make it a much more straightforward job to manage keywords over time and track search volumes. Wordtracker also presents raw search figures, while Google applies unknown extrapolation to its (unknown) search sampling. In terms of reliablilty - while some people say that Wordtracker's database (at just under 1% of US search) is too small, others do find it very useful, and we've had comments from users saying that they've managed to find useful keywords that nobody else is using, and so maximise their presence for those searches. While the dataset can be perceived as being small, it's generally considered to be representative. No keyword research tool is going to perform brilliantly across all niches, but Wordtracker has customers returning time and again to use the service. I hope this is helpful, but perhaps a good way for you to answer your own question would be to take our free 7 day trial, which gives you full access to the tools and database. If you have any questions, you can mail us at support[at]wordtracker[dot]com All the best, Mal
These tools are supposed to give us the search volume on Search engines, and specifically Google Search Engine. The Google keyword tool surely has access to its own database and therefore the results are obviously reliable. I find Google Keyword tool perfect for the job. Important: I don't have much experience with Wordtracker.