I’m a big fan of the Google Webmaster Central Program and using sitemaps. I agree that you should build your website so that it is crawlable and not rely on sitemaps to compensate for poor site architecture, but hands down there is no better tool when you are migrating or cleaning up after a site migration than webmaster central. However there’s a dark side to webmaster central that I haven’t seen anyone else bring up.
First we need to dive a little deeper into webmaster central and sitemaps. One of the subtle features of webmaster central is the priority tag in the XML file. You are allowed to specify a value from 0.1 (lowest) to 1.0 (highest) for your pages. Now some people try to “trick” the search engines giving all of their pages a 1.0 thinking this will result in a SEO benefit. This is completely incorrect, as they are scale values. If all of your pages are 1.0 you have told Google they are all equally important, and that there is no priority. So you are much better off playing by the rules on this one.
Some sites generate XML files manually or use an automated tool to generate the pages interfacing with the CMS. If you are using wordpress you can get the Google Sitemaps Plugin to do this automagically for you. It even takes care of pinging Google and the other sitemaps programs from Yahoo and ASK as well. However out of the box the program uses number of comments as the priority calculator, which is well just bizarre, and almost always inaccurate. However what you can use for better results is the Alex King plugin called Popularity Contest to give you a more accurate priority calculation. Popularity contest uses number of page views to determine priority, not perfect but IMHO much better.
So here’s where the competitive intelligence comes in, people who are using automated solutions like popularity contest are telling you their most highly trafficked pages. Other people who are generating Sitemap XML files in a more manual fashion, are telling you the pages they want to rank. Chances are good the pages they want to rank for are the “money pages”. Now of course you could cloak … err … IP deliver your sitemap file, but IMHO that’s about as smart as trying to pick pockets at a police convention. So there you have it a little something extra to look at the next time you do some competitive analysis.