Google Analytics is a great tool for analysing your website audience and performance. The service now offers something called Advanced Segments which you can use to get a more indepth understanding of what is happening.

Here’s a great article with some helpful tips on how to do this :

What are Advanced Segments in Google Analytics and Why Should You Use Them? | SmartData Collective

http://smartdatacollective.com/dfasso/45056/what-are-advanced-segments-google-analytics-and-why-you-should-use-them