One of the nice features of FFDirect is automatic URL-tagging the links in your posts published to friendfeed and make them appear as a separate "campaign" in your Google Analytics reports.
Once you've installed and enabled FFDirect, go to Settings->FFDirect and check "auto-tag URLs for Google Analytics", and you're done!
After you've published a post or two with FFDirect enabled, check your Google Analytics reports. Go to Traffic Sources -> Campaigns and you should see something like this:
(you may have to wait a couple of hours for Google Analytics to create the latest report)