Amid the wake of Overture Keyword Tool‘s apparent demise, another tool emerged to provide useful measure of competitiveness of a given keyword.
As it is unclear to many what do these numbers represent, Wordtracker also provides an explanation on how the numbers are computed.
Every day, on average, we collect about 3.34 million search terms from Dogpile.com and Metacrawler.com, who according to Netapplications.com account for 0.63% of searches across all engines. By combining these two figures, we estimate that the total daily searches across all engines is 529.4 million.
This WordTracker tool should be a good alternative to Keyword Discovery though I would still prefer to use the latter.