As a fiction writer, it is important to know your audience. If you have never done any research to discover what demographic your proposed novel might reach (or not reach) then you may be wasting valuable time writing a novel that no one will read.
Google Zeitgeist is a fantastic engine created to show researchers at a glance what subjects people are typing into search bars on a moment to moment basis. The 2011 numbers have been out for a while and you can see what people were interested in throughout that particular year. (See above graphics) You can even see what is going on right now in trends on Google through the following link.
I use Google Zeitgeist to plot what trends are hot so I can consider including these things in my current novel. I am writing a post-apocalyptic story, so I have to look at major events and figure out a realistic progression of those events or how things might come to a catastrophic end. For example, if I go to the Google Trends site and type in the word "doomsday" and then select "last 30 days" I find out that many people have been reading about this subject recently. Google shows a handy graph of how many people have searched for that topic in the last 30 days. I can type in any news topic from Libya to Mitt Romney and get data which will tell me how well or how badly that subject is trending.
It also tells me which topics are slowing down or are not as important to Google searchers. This can be helpful as well, as I will be watching the topics of apocalypse and doomsday and how important they become over the next few months. I am predicting that as we get closer to Dec. 21st 2012, the topics searched will trend more swiftly to doomsday topics, even if that day doesn't spell the end. (wink)
It is important to stay connected to what the world is thinking if one wants to strike a nerve with the reading public. I am not sure if this research will benefit my latest novel, but at least it is an interesting tool with which to experiment. It doesn't take long to access and use the tool, so I suppose the time used to do so is not time wasted. Any research into your market is better than no research at all.