When a player retires or moves to a different city and team, newspaper ad usually follows. Typically, the player is the one purchasing the newspaper space to thank the city's fans for their career. We almost expected the recently retired Calvin Johnson to do the same, but Calvin Johnson isn't a typical player.
It speaks volumes that the one who took out a newspaper ad on the Detroit Free Press was the Detroit Lions and not Johnson. The Lions are definitely grateful for Megatron's NFL career.