here is my tip since joining the rewards network...

1. So far..i have used my debit card on all of the programs...I just have to add it on whenever i want to use it for that specific program and have to make sure that its deleted on the other programs (so far its worked for 3 different programs)

2. I don't think it matters if the card is active or prepaid..the program just wants at least one card number in it..since if u don't use it then it doesn't get charged its doesn't matter if a prepaid card doesn't have money in it..

3. I use prepaid visa/amex cards to keep my rewards network programs i'm not working on active...

4. Tip for you newer users..next time American express small business saturday comes around be sure to start new programs and sign up for the bonuses..then use your amex small business saturday 25$ credit at a small business on the rewards network list...easy way to get the bonus without spending money...I would suggest 25$ gift cards