Interesting results from tracking Google searches for Karl Marx vs. Ayn Rand. In the chart below, Marx is blue, Rand is red. The orange line is a baseline search for recession:
The cycles on the Marx hits match up neatly with university schedules—people are googling Marx for class, not so much on Ayn Rand.
Here are the exact search terms:
For Marx, we'll use all of the following terms: "Das Kapital", "Das Capital", "Communist Manifesto", Marxism, Communism, "Karl Marx", "Carl Marx". For Rand, we'll use: "Atlas Shrugged", Objectivism, "Ayn Rand", "Ann Rand", "The Fountainhead", "Virtue of Selfishness", "John Galt". I think that's a reasonably comprehensive list of terms folks would be looking for, but feel free to try your own variations. If you include only Marx, be sure to run the "-Groucho, -Richard, - "Marx Brothers"" and so on.