Keyword Research as a Predictor of Sales
Here's a short but important note about relying on keyword demand to predict general industry sales trends or successes.
Sometimes, keyword demand is a fairly accurate reflector (or predictor) of interest and/or sales:
Stats: According to this game industry blog, here are the respective console sales for 2007:
Wii: 6.29M units
Xbox: 4.29M units
PS2: 3.97M units
PS3: 2.56M units
And sometimes it is not:
While this chart might correspond roughly to the sales of player units (578,000 HD DVD and 370,000 Blu-ray machines will be sold by the end of [2007]"), one would be advised against picking a format "winner" from this chart (see this or many other articles like it). Most of the technorati (small "t") realize that a PS3 console also comes with a built-in Blu-ray player, so those searching for [blu-ray] are only a fraction of those searching for Blu-ray. If that makes sense.
Disc sales tell a story different from the sales of hardware units. PC World says "Blu-ray Disc movie titles outsold HD DVD in the United States by a nearly 2-to1 margin last year, according to sales figures from Home Media Research."
Using trending charts to estimate sheer search volume is a pretty sure bet. But be careful about drawing conclusions about popularity and intent out of those raw numbers.