Well, McDonald's used the easy way out, and it worked. The summer is hot, the temperatures soaring, you want a refresher badly, and it helps it is photographed on a sandy background. "Keep your cool" - again a lowest common denominator copy - helps spell it out. The ad has almost no concept, and it works in its favor, because well - all McDonald's had to do is just show nice, appetising things one wants to eat in the summer. I think I am calling 1297...