I believe that Amazon Payments is the only system that lets you pay someone with a credit card, although it's limited to $1,000/month (otherwise people abuse it, sending cash to each other to rack up points on their credit cards).
Otherwise I could deposit $10,000 from my credit card into my on-line gambling wallet, then withdraw it, repeat...
But yes, you also will not earn points on balance transfer transactions. But they typically are processed via ach.