A Web analytics program is like an airplane pilot's navigation system. As pilots look to their dials and scopes to steer the plane, site owners monitor the data from their Web analytics software to help them run their site.

An analytics program — like those by WebTrends, ClickTracks, Omniture, Google and others — outputs ever-changing data about a site's traffic patterns, unique visitor numbers, bounce rates, referring URLs, and other user trends.

But, like a pilot's dashboard, no one ever said using a Web analytics program is easy. These programs display torrents of data, row upon row of numbers. Even analytics experts admit that they're complex and can be confusing.

Your analytics program tells you which search terms are sending traffic your way, but it can't tell you which popular terms you should be using but aren't.

For example, if you sell Tom Cruise ceramic figurines — but no Tom Cruise glass figurines — you're not aware of all the people searching for 'Tom Cruise glass figurines.' If you get no traffic for a term, your analytics program will give you no clue to this horde of users.