"With Yahoo Clues, you can discover and compare trending information for search terms of interest to you, or explore popular trending search terms on Yahoo. You can see search volume charts, demographic graphs, maps, or even related searches specific to a demographic group. We're also experimenting with an interesting feature called Search Flow, which offers a unique look at people's search patterns and the next most probable search term people try after searching for a query," informs Yahoo.
For example, if you compare the queries [Google Buzz] and [Google Reader], you'll notice that Google Reader is much more popular than Google Buzz, it's not very popular with teens, but it's very popular with women, which is rather peculiar.