One simple tool reveals a great deal about the effectiveness of a Web site.

Yahoo! Site Explorer is useful for measuring the size of a site, how effectively it is being distributed and how good it is at acquiring inbound links from other sites.

Among other uses, the tool tracks Pages and Inlinks. Pages are the documents that have been indexed by Yahoo! search. Inlinks are the links coming to your site from outside sites.

As a test, I chose two media sites that have similar market sizes and are located in the same state. One has Pages at 82,700 and Inlinks at 17,300. The other has Pages at 245 and Inlinks at 45,200.

What a remarkable contrast.

The first has a relationship with Yahoo! that includes a feed of all of its documents, which accounts for the high number in the Pages category. But the site was revamped last year and lost many external links because the navigation and naming convention for pages were both changed during the transition.

The second site does not have a known relationship with Yahoo! and does not appear to be using the feed tool that the portal provides, which would explain why so few pages are indexed within Yahoo! But the second site has been around a long time and has not made any major or obvious changes to its navigation or naming convention. As a result, its Inlinks are nearly three times higher than the first site.

Yahoo! Site Explorer is one of many effective tools for tracking and improving the performance of any Web site.