The system knows about some buildings as landmarks. I don't think I would categorize that as advertising; "turn left at the Starbucks" is an extremely human way to give directions. I haven't thought about it as advertising when my parents tell people to turn left at the gas station on the corner; There's a gas station on the corner. It's an easy landmark.
Two nights ago, I had Maps tell me "turn right after the McDonald's" because there was a McDonald's at the corner.