Yes, it's very important to add a second word to benchmark the first. It doesn't take
that much traffic for a term to appear on Google Trends, so without a known (or guessable) reference point it's a meaningless graph.
For example, everyone is talking about Youtube (there are thousands of articles about it and it's all over the blogs) yet in reality it's much much less known than Myspace is...
http://www.google.com/trends?q=youtu...o=all&date=all