Google Trends (trends.google.com) is a product from Google that allows users to look at how query term volumes have changed over time.
To use Google Trends, type one or multiple query terms (separated by comma) into the search box, and click the “Search Trends” button. A graph displaying the relative number of times this query term(s) was searched since the beginning of 2004 is shown. You can also view the query term distribution by region (this is basically country), city, and language.
Using Google Trends, a user is able to:
1) Understand the relative search volume of a query term over time.
2) Understand seasonality of query terms.
3) Compare multiple query terms.
4) Examine how the above trends vary with geography and language.
Many people can benefit from this tool, from SEOs doing keyword search to marketers understanding seasonality trends. Personally, I use this tool sometimes just to satisfy my own curiosity. For example, by typing in “nfl, nba”, I found that NFL is more popular in the U.S. than NBA. In virtually all other countries, though, NBA is more popular (i.e., searched more frequently) than NFL.
One thing to note is that Google doesn’t give out the absolute number of times each query term is searched. This does not diminish this product’s effectiveness.