.....I remember when there were a few Independent bookie who would lay you and would hold the card and not take the cash until you lost .....
The reason the bookies did that was to avoid paying CC fees on winning bets.
Fer instance if a punter had a bet and it lost, it was simple the bookie charged his card after the selection lost and the bookie paid the CC fee.
If the bet was a winner, then the money was held 'On account' until such time as the client requested the funds be returned to his account.
The thinking being all the time was to avoid paying the bank CC fees.