What’s Up With Bags of Ice for Sale at Fast Food Restaurants?

Just recently I noticed on the sign at the Burger King in Okemos that they're now selling "Bagged Ice". That seemed odd to me - why would they be selling ice at the BK?

Then over the weekend, I see that Arby's in South Lansing is also selling bagged ice.

What am I missing? Why is this now a 'thing'?