Keyword phrase research is perhaps the most important part of any Search Engine Marketing campaign. The ability to pinpoint the phrases used by searchers seeking a product or service is invaluable both in paid Search and Organic SEO. Unfortunately, the majority of the available services are lacking when it comes to bet-the-farm-on-it certainty of search numbers and predictions.
Most SEOs and Paid Search marketers will cite WordTracker is the default best available software out there, although some competitors are starting to make headway, such as Trellian's Keyword Discovery tool.
Keyword, Search Engine Marketing