Patterns.
This is a visualization of the Google Computers & Electronics Index that tracks queries related to "windows, download, mac, hp, microsoft, ipod" and so forth.
Notice the spike at both Thanksgiving and Christmas? Notice the gap between both dates getting deeper? Which means that the month long shopping orgy is no longer lasting 30 days. I am amazed at the correlation between searches and behavior, but then again I am not. It makes sense, but even more when you see it in all its glory, courtesy of Google.
