When making my reservations on Orbitz.com I was allowed to pick my seat. So I picked 7C. I had just a 41 min layover so needed to get off plane and make it to the next flight. When I checked in online it stated that I had seat 24C one of the seats in the very back of 5he plane. There was no mention that seat 7 C was a premium seat when making the reservation. Upon arriving into SFO the plane was early but then we had to wait on the tarmac for 30 minutes. I had time for a pit stop then right onto the next flight. No time to get a snack/beverage for the flight. The United employee said the doors were closing in 5 minutes!