Comparing the two services, Google Analytics and Webmaster.

Google analytics involves putting a javascript code in every page you want tracked.  It doesn't work if people turn off javascripts coming from google-analytics. com.  Google loads a much bigger chunk of javascript into the page -- take a look, eg.  with Firefox's Firebug tool.  It's interesting.

Analytics is more for people who (and companies that) are trying to promote their site in various ways, and the Google paid services are pushed.

Google webmaster requires posting just one HTML page on your site, to verify that you can upload pages to the site.  Then it provides the same sort of information you could get using Google advanced searches (e. g. , outside links to pages on your site), but in a much more compact way with various types of info provided.

I find them both worthwhile, but I had them confused for a few days.  I had joined each at different times, and wondered why each had a different set of sites. . .  (I found iWebtalk in a Google search to see what comparisons others make between the two services, and found a closed thread here that didn't really answer the question. )