Customers will still need a smartphone to make their payments, of course. The in-person payment option works by going to the "Pay Bill" section of the XFINITY My Account app, where users can download a barcode for the amount they'd like to pay. A participating 7-Eleven will scan the barcode, take the payment (plus a $1.25 fee for every transaction) and send a digital receipt to the customer's phone.

"About five percent of our customers prefer to pay their bills in cash each month," Comcast's VP of Customer Service strategy said in a release. "This new partnership gives those customers a payment option that is convenient and simple."

Now that Comcast is being sued in Washington State, more customers might actually want to consider paying in cash -- part of that $100 million lawsuit alleges that the cable company harmed some customers' credit scores by conducting unnecessary credit checks.