Rakeback is a bonus that is accrued for each bet, it does not matter if your bet is winning or losing you will still get a piece of your bet back.
The rakeback is calculated in the currency that the player is playing with, and it is calculated as follows: Wager x 1% (house edge) x 5%.
For every bet that you place on the casino, you will receive 5% of this house edge back.
The minimum amount of rakeback that can be claimed is $1.