I like to use Google Analytics, but the boring stuff is that when you switch themes, you’ll have to re-insert the code in the new theme. To avoid it, let’s use the power of WordPress hook to insert our analytics code without editing theme files.
Good web developers know that even the most beautifully designed page is worthless if it takes too long to load.
To help you optimize your pages, Google has announced a new Labs feature in Google Webmaster Tools designed to track page load speed. The new Site Performance tool is one part tracking and stats tool, and one part Firefox add-on.