Brothers and sisters wouldn't be beneficial in the eyes of Jehovah to use your credit cards to give to his life saving work rather than spending it on worldly pleasures such as food, clothing, shelter and travel ?
Wouldn't you rather see the GB heads and their wives live in a comfortable living condition, such as a swimming pool and tennis courts, vehicles to drive and all pertaining health costs as they age ?
These things do cost money brothers and sisters, so offering your financial help and support would be greatly appreciated and would show your personal devotion to witnessing work as described within the bible..