Sometimes I look at Google HotTrends and it's interesting to look at what is suddenly "hot" but what's often missing, despite Google's attempt to add that information, is why something is happening, why it's hot, and what's driving the HotTrend - for that, most of the time - human analysis is needed.

Or it could be what you know.  Here's an example - last Thursday, November 1st, it so happened that the term "federalist papers" was #3 on Google HotTrends and it peaked at about 8:30 PM EST time (no location was given - sometimes, Google HotTrends gives us a location).

Looking at the search results and news citations actually did nothing to tell me why Federalist papers was peaking on November 1st around 8:30 PM.   Not one listing in news articles (left), blog posts (right) or web results (bottom half of page) gave the actual reason.  

The reason = Clay Aiken Was Great on “Are You Smarter Than a 5th Grader?”  - turns out the question was asked to Clay Aiken while he was on the "Art you Smarter Than a 5th Grader" show and his fans and TV/Internet audience did  a query on Google to find out about federalist papers since he had a lot of money riding on the answer - which I think he got correct (but I didn't watch the show).

Ok, here's my point - while Google tries to link in what the trigger, or cause of a traffic spike on a term is - it's often unsuccessful - that only understanding - only knowledge of a circumstance - often, can make the connection between a spike in demand for a term (or for anything) and the real cause of it.

Knowing the cause of traffic spikes can often tell you what they mean to you - that's why it's good to know - but it's also clear that much more work needs to be done to co-relate the demand for terms spurred by current events - and the result on Internet Searches - and the current technology, although not bad, is certainly not up to the task yet.

I would suggest using the Google Alert database to key into Google HotTrends along with TV/Cable/Radio plays, if possible - as I've noticed that much of what becomes a HotTrend in Google is driven from a media event - watching a local movie that's aired, or something that is in the movies, or a world event.  Sometimes, linking the spikes with those events is easier - but in many cases, it's not - because there's a missing piece of information, like Clay Aiken's answer of the "federalist papers" question.