Google Services
Did you know that many of the most powerful webmaster tools are free? Google Analytics, Google Apps and other tools for webmasters (Gmail, Google Maps, Custom Search etc.) are some of the most powerful information resources for any webmaster and they are all absolutely free. I use them for both my own sites and my client’s websites. Even if you don’t use any other Google service, I suggest that you use Google Analytics on every website to receive information about how Google sees their website as well as how it is performing.