I suspect that we are getting substantially more conversions than is actually reported by the counter. i.e. from customers who have disabled their cookies and also from content sites.
Does anybody have any figures on how much does the conversion counter underestimates actual conversions?
My guess (and this is pure opinion, not based on research) is that the percentage of Google users who do not accept cookies is quite low. IMO, probably in the single digits.
These are the averages for the sites that I track. The average percentage of those who don't accept cookies for non computer related website visitors is between 2-4% (median last month was 2.4). For computer related websites, they ran the gambit of 3-6%.
The site that ran a 6% no cookie acceptance rate, has a decent number of visitors viewing the site via non traditional means (pdas, webtv, etc).