You can't. If a person on your downline wants to quit or give up, let them and concentrate your efforts on the affiliates that have not made that decision, but are looking for a path to success. The worst thing you can do is try to delay the inevitable, especially by trying to "buy" their way to success by giving them gifts such as TCredits or Gift Certificates. Give these as rewards to the affiliates that are not going to quit or give up but are going to chase their dreams!