How much do you typically buy on the Chase card each time, and per month?
I didn't mainly do it for the miles. The situation was as follows. I had a relatively high debt to credit utilization(close to 50%). A lot of it was on my Chase freedom card. Being that the United Mileage Plus card didn't have an official credit line, rather a credit
access line(which doesn't post as "revolving credit" on the credit report), I used it to purchase coins and pay completely off the freedom card and other cards.
I did it almost every 10 days for a few months. Doing a balance transfer would have hurt my credit(hey, I got miles as well).