Keyword Research – Search term research is a fundamental activity for a successful search marketing campaign.

You need to know the keywords people are using if you want to target them effectively.

Google expanded Google Trends (another excellent research tool) with Hot Trends.

Both Wordtracker and Keyword Discovery have fee-based keyword research tools.

The Wordtracker Free Keyword Suggestion Tool for [cars] tells me these figures for daily searches:
cars: 73,994
used cars: 27,871
car: 23,767
fast cars: 15,056
car rental: 10,647

The Keyword Discovery Free Search Term Suggestion Tool for [cars] tells me these figures for yearly searches:
cars” 1,036,784
used cars: 322,583
new cars: 86,787
fast cars: 69,364
rental cars: 60,904

The downside to both tools is that I’d like to see them provide more information about where the data comes from and how up-to-date it is (for WordTracker, I think it is based on daily searches averaged over the past two months).

Instead, the numbers are just guides as to the popularity of terms relative to each other. From WordTracker, [cars] is roughly three times as popular as searches for [used cars]. Looking at Trellian, you can see its figures show approximately the same percentage. Looking at figures from several services can give you a better idea, in general, of what terms you ultimately decide are popular enough to target overtly.

Also see
Bing Webmaster Tools: A Comprehensive Guide
Google Power User Tips: Query Operators

Post excerpts from Danny Sullivan