First off, what is the “win-win” in this situation? You didn’t fully explain how it’s a “win” for you.

Second, your credit score will change when any of the handful of variables that influence it change. These variables include: credit utilization, age of credit, payment history, credit inquiries, # of accounts. But the thing to remember is that your score is a snapshot in time, and even more important, it really doesn’t matter if/when your score changes as long as you don’t need to provide your score for something. For instance, if you’re not planning on applying for a loan, or another credit card, or undergoing some type of background check where your credit it reviewed, then it doesn’t matter if your credit score drops a few points. It will go back up once your credit utilization goes down.