In 2008, Burger King released a meat-scented cologne called "Flame."
In 2004-2005, McDonald's paid rappers to mention Big Macs in their songs and paid them $5 each time their songs got played on the radio.
3Big Mac Index
In 2011, Argentina's government forced McDonald's to sell Big Macs at artificially low prices so that the country's performance would appear better on The Economist's Big Mac Index.
McDonald's is basically a real estate company: "We are in the real estate business. The only reason we sell hamburgers is because they are the greatest producer of revenue from which our tenants can pay us rent." - Harry J. Sonneborne, McDonald's founder.
The reason why breakfast isn't served all day at McDonald's is mainly because the grill temperature required to cook beef patties is significantly different from the temperature at which eggs are cooked.
In 2009, Burger King launched a campaign that if you unfriended 10 friends on Facebook, you were entitled to a free whopper. The ex-friend would then receive a message explaining that their friendship was less valuable than a whopper.
McDonald's burger doesn't rot and it’s not because there are any mysterious chemicals in it, but because low moisture and dehydration basically turn it into a jerky.
Muhammad Ali, being refused a hamburger and told, "We don't serve negroes", replied, "That's OK. I don't eat 'em."
The Economist has an indicator of the purchasing power of a country measured in how many Big Macs could be bought in that country with $50 USD - The Big Mac Index.
In 2009, Microsoft promoted Windows 7 in Japan by partnering with Burger King to release a 7 patty Whopper.