In Slate, Michael Idov explains why trying to run your own café is insane.
Discarding food as a self-canceling expense at best, the coffee needed to account for all of our profit. We needed to sell roughly $500 of it a day. This kind of money is only achievable through solid foot traffic, but, of course, our cafe was too cozy and charming to pop in for a cup to go. The average coffee-to-stay customer nursed his mocha (i.e., his $5 ticket) for upward of 30 minutes. Don’t get me started on people with laptops.
Happolati's Miscellany 