jamesMP - 7:23 am on Aug 22, 2013 (gmt 0)
Depending on your traffic levels, you may also wish to adjust the sample rate. Add this line to your tracking code:
Where 50 = 50% = one in two visitors (or whatever is appropriate).
More details here https://developers.google.com/analytics/devguides/collection/gajs/methods/gaJSApiBasicConfiguration#_gat.GA_Tracker_._setSiteSpeedSampleRate