Potentially yes, but would it happen in practice?
Sure, you may not actually donate in practice. But you could (with just a small amount of extra effort) set up your bank account to automatically transfer a certain amount of money each month to SIAI. If the rewards program for the credit card gives less monetary value than the best rewards program you have access to, then you are basically paying the credit card company because you are too lazy to set up an automatic transfer for your bank account.
In my mind, this would amount to paying the credit card company a monthly fee in order to help you overcome a...
Luke posted about this on SIAI blog. Essentially, you can get a credit card with cash-back rewards program that automatically donates money to Singularity Institute.
This seems to me like a dream come true. Am I missing something? Are there any catches? Is there a better rewards program, which I can use to save more money, so I can donate more money to SIAI?