Admitted, being born in New Jersey and growing up mostly in California, I find the idea of not having access to a coast stifling. I think some exceptions may apply to Chicago and Detroit because they are near the Great Lakes. The first time I ever heard someone call their carbonated soft drink pop was when I moved in with my grad school roommate in 2004. She, like my husband, was from Michigan. I contributed this quirkiness to them both being from an innerstate. While the Great Lakes are really big, they still aren’t oceans.
You can see the map of generic usage for carbonated soft drinks:
I have a bias against those who would call any carbonated drink coke. Don’t ever call my Sprite a Coke!! The main exception to that would be my grandma, who was originally from Georgia. Nobody steps on grandma Sara’s toes.
You can participate in the ongoing study here.