How do we know this stuff?

The music software popularity index is based on recent Internet search activity on Google, Yahoo, AOL & Microsoft. Collectively these 5 search engines represent more than 95 percent of the searches on the Internet. For the products that we track in this index, most of the internet traffic comes from Google. Over 100 search terms are used to construct this index. Here, for example, are the top terms used in searches for Apple Logic.