How many cups of coffee are sold in New York City each day?

I'll estimate how many cups people in the city drink in a day, then take the share that's bought and not made at home. There are about 8 million people in New York City. Commuters and tourists add roughly another million on a weekday, so I'll use 9 million. About 80% are adults, which is around 7 million. I'll say about 4 million of them drink coffee on a given day, and they have two cups each. That's 8 million cups. The 4 million is 60% of adults, which gives 4.2 million, rounded down. Not all of those are sold. I'll say about half are bought. The first cup is often made at home or poured free at the office, and the second is more likely bought on the way somewhere. So that's about 4 million cups sold a day. That seems reasonable for a city that size.

I'll estimate how many cups people in the city drink in a day, then take the share that's bought and not made at home. There are about 8 million people in New York City. Commuters and tourists add roughly another million on a weekday, so I'll use 9 million. About 80% are adults, which is around 7 million. I'm leaving out kids, who drink very little coffee. I'll say about 4 million of them drink coffee on a given day, and they have two cups each. That's 8 million cups. The 4 million is 60% of adults, which gives 4.2 million, rounded down. Not all of those are sold. I'll say about half are bought. The first cup is often made at home or poured free at the office, and the second is more likely bought on the way somewhere. Commuters and tourists buy nearly all of theirs, which is another reason half isn't too high. So that's about 4 million cups sold a day. That's a weekday. On a weekend most commuters stay home and offices are closed, so I'd take it down to maybe 3.5 million. As a check, suppose around 20,000 places in the city sell coffee, counting cafes, delis, carts and fast food. That's 200 cups each a day. A busy cafe sells far more and a corner deli far fewer, so the average is believable. The assumption that moves the answer most is the share bought. If it's 60% and not 50%, we're closer to 5 million.