“I have been using search engines to track interest for a subject for a long time. I have done this manually by searching for the same term at regular intervals, keeping track of the amount of hits and look for any significant growth.
Google talks about how many searches pr. day for specific words and phrases to track popularity, still I haven’t really found a service that can give me a historical view of the amounts of hits on a subject.”
If anyone knows of similar services, let me know!