Unfortunately, things like DRINKS, sell infinitely better when you can walk into a 7-11 and pick it up.
Number of drinks I buy a month at a gas station: 5-6 Number of drinks I've bought in my lifetime online: 1 (Was a free addon to a thinkgeek order and tasted like crap).
I bet more drinks are sold from the 7-11 outside my old office building in Boston (Downtown Crossing)than thistmonger sells across all categories in a year. If someone wants a drink, they don't want to wait days to get it. It's a major impulse buy category.