londrum - 9:20 pm on Jun 22, 2007 (gmt 0)

bear in mind that some ads don't convert straight away. especially if they're advertising expensive products. people like to do some research, do some window shopping at other sites etc, compare prices, and then maybe come back later and buy it.

so your ads might still be bringing in the sales -- it just takes a while for people to convert in a way that doesn't get logged.
think about the last time you saw an ad and brought something straight away from it. you might see it a few times before you actually do something about it.