Total lifetime earning Cashback decreases are due to:
1. Cashback first tracked at a higher amount and recalculated during the validation period based on customer’s tier or item purchased
2. Cashback has been rejected
3. The Cashback is tracked at AUD0
4. Wrong ShopBack account
5. Certain merchants with monthly Cashback caps will affect your lifetime earnings when the Cashbacks are validated on a monthly basis.
Depending on merchants, Cashback tracked at a higher amount will then later be recalculated at the correct amount upon validation. Hence, this may be the reason why you experience the difference in your total Cashback amount.