Originally Posted by DamageX

Actually, there will ALWAYS be a discrepancy between hits sent and hits counted by the receiving parts. Ask anyone who's been trading traffic for a while and they'll tell you that what one trade script counts as sent, the receiving trade script will likely count only 80-90% of it. If you also use a third-party webcounter, such as extreme counter or whatever, which relies on the visitors loading a remote image (hosted on the counter service's server) then you're very likely to see even less received.