This is off-topic but I just want to mention that I participated in a promotion of exactly this sort. I had contact with over 900 customers - personally - and exactly zero of them accepted the offer.
So if you are in a position to have any influence on the decision of whether to even offer or launch this campaign, I'd consider doing some testing. Try it for a day, and if you get zero nibbles, stop bothering your questions with what many customers will think is an invasive and irritating line of questioning. For instance, consider the info you don't have here. You're saying that if you see that the customer has a balance available to spend at your bank, then you would offer them the ability to transfer (a totally imaginary) higher APR balance from some other card. So you're fishing in the dark there, having no idea if they even have any other credit cards or if those cards have a balance. This approach fails the most basic tenets of salesmanship, as far as identifying a need before offering a service.
So, if you're stuck with that limitation, then unless you have a significant incentive to offer - like "Get a $50 statement credit if you accept this fabulous balance transfer offer," I think you're wasting your time. [I don't know if such an offer would even be legal, by the way - I'm just saying unless there is something obvious the customer will "get" for listening to your pitch, their answer is likely to be, "No, no, shut up, I just called to get my checking balance."]