Regardless of what anyone says ... size matters. The more unique, relevant content you have on your site the more relevant your site will appear to the search engines and the more phrases you'll have a chance to rank for. With this tool you can easily compare your size to those around you and check which pages you (and they) have indexed by the engines. Remember though, relevant and unique content counts more so you don't need to be as big if you know how to use it (your content we mean).