If your transaction seems to have tracked, but it has only ever been displayed as zero then this can mean several different things.
(Please note: This is different to your cashback having tracked at a value, but then being crossed out or replaced with zero - please follow appropriate link below for this scenario).
Several merchants report 'leads' or quotes as a transaction event. This means they are reporting that they have detected that you clicked through from TopCashback to their site - but they are not yet reporting that they have tracked any transaction entitled to cashback.
On the whole it is normally quite a good sign that the merchant has detected your click through - but if no cashback value is reported then it is best to lodge a Missing Cashback Claim before too long.
« TopCashback FAQs and Help Overview