From an interview with John Sculley (CEO of Apple before they brought Steve Jobs back):

One of the things that fascinated him: I described to him that there’s not much difference between a Pepsi and a Coke, but we were outsold 9 to 1. Our job was to convince people that Pepsi was a big enough decision that they ought to pay attention to it, and eventually switch. We decided that we had to treat Pepsi like a necktie. In that era people cared what necktie they wore. The necktie said: “Here’s how I want you to see me.” So we have to make Pepsi like a nice necktie. When you are holding a Pepsi in your hand, its says, “Here’s how I want you to see me.”

We did some research and we discovered that when people were going to serve soft drinks to a friend in their home, if they had Coca Cola in the fridge, they would go out to the kitchen, open the fridge, take out the Coke bottle, bring it out, put it on the table and pour a glass in front of their guests.

If it was a Pepsi, they would go out in to the kitchen, take it out of the fridge, open it, and pour it in a glass in the kitchen, and only bring the glass out. The point was people were embarrassed to have someone know that they were serving Pepsi. Maybe they would think it was Coke because Coke had a better perception. It was a better necktie. Steve was fascinated by that.