McDonald’s Egg McMuffin turns 40 this year. Adweek took look at its history:

• In 1971 McDonald’s executives were trying to figure out how McDonald’s could build a breakfast business.
• The Egg McMuffin was the answer. After the initial challenge of convincing customers to come to a fast-food join in the morning, the item was a hit, and now breakfast items make up 25% of McDonald’s sales.
• The Egg McMuffin is so popular that the company is considering making the item available all day.

Read more about the pale imitation that is the Eggwhite Delite, how McDonald’s competitors caught up to it, and more over here.

Source: AdWeek