Google Analytics is very interesting, but I find it very hard to find any "action items" there. Mostly I stare and wonder. On the other hand, Webmaster Tools has helped me fix meta tags, fix my site maps, fix some linking problems, drop unwanted forgotten pages, etc. Which do you find to be the most useful? Can you suggest some "concrete action items" that one can do, by studying Google Analytics? I am sure there must be some, but I can't seem to find them. . .
They both have features that will help you focus your efforts to improve your site. For example, one way to come up with "concrete" action item using Google Analytics might be to study which pages besides your main page get a lot of hits. Perhaps your action item is to focus on improving those pages. Or, perhaps your action item is to figure why other pages *don't* get the hits and focus on making your navigation more effective. The list is nearly endless.