The Easy Way to Learn About Your Traffic

Are you trying to understand your website traffic?

I am a big fan of a service called Quantcast. 

From their website:
Quantcast is a new media measurement service that enables advertisers to view audience reports for millions of sites and services to build their brands with confidence.

This service is incredibly useful for the public sector.  Here are just a few interesting uses:

1) Understand your own audience using the demographics tab
2) Understand how your audience overlaps with the audiences of other websites.  This allows you to identify websites you might want to target for collaboration (our company, GovDelivery, allows public sector clients to collaborate and cross-promote with each other so we use Quantcast to see audience overlaps between different websites)
3) See the frequency of your visits.  Quantcasts classifies visitors between addicts, regulars, and passers-by.

In my experience, the service undercounts website traffic by 30-60%, but it is still directionally accurate, and it gives you excellent information about your website and the user traffic of others.

I welcome any feedback on how you make use of this service and how the numbers you see from your own analytic tools compare with what Quantcast is telling you about your website.