Had the same idea for a cafè at the beach we visit often. Reserve your place in the queue without having to actually stand there. Then again, if people don’t have to pay the price of standing in line, wouldn’t the line just get longer and longer? Maybe a better approach would be to send in orders. And the business accepts them based on availability and order size. If it’s busy and you just want a coffee, you won’t get a seat. But you will if you’ll order three burgers plus drinks.