CEO James Quincey told investors this week it was because Diet Coke has tapped into the millennial market with targeted marketing and “flavor innovation” such as Ginger Lime, Twisted Mango and Feisty Cherry. Quincey also cited the fact that earlier this year, Diet Coke came out in a new “sleek can” that presents a “more modern, more engaging package.”

The packaging changes were encouraged in part by rising metal costs that encouraged the company to “bring some innovation into the packaging” and adapt to changes, Quincey said.