Hi Duncan

Yes, we've been through the ABCe audit process (PDF of certificate here).

I would certainly say that using cookies to try and identify unique users is more accurate than using IP addresses, though still far from perfect, particularly over longer periods of time. (for more on this see the RedEye research).

The problem with IP addresses, particuarly  for "consumer" ISPs, is that the IP address for any individual user is likely to be different every time so they will appear to be more than one user.

The bad news about the above is that if you have been using IP addresses for unique user authentication then when you switch to cookie-based authentication then, more than likely, your unique user figures will drop. Quite possibly they'll drop quite a lot - so you'll need to manage expectations! (it shouldn't really affect page views though)

All the best

Ashley Friedlein
CEO
E-consultancy.com

On 08:53:36 15 January 2008 DuncanB wrote:

For the last few years my company has undertaken an ABCe audit twice a year. We have always submitted log files for the audit data. We are now considering moving to auditing using cookies as we are unsure about the reliability of using IP addresses (our main target audience is the middle east where ISPs are less advanced than the UK...)

Does anyone have any experience of ABCe Audits and the pros and cons of auditing via log files or cookie?