As mentioned before it is a useful resource location tool. Not only does it allow you to hunt down an item of interest but it also gives you a list of resources that are related to the original data. For example, if you were to search for the game "The Hobbit" in Infoseek, it will not only give you the download links to the tape images, but also list instructions, inlays, screenshots, reviews in magazines, company information, among other stuff.
You could also search for authors, books, companies or hardware titles.