Each seat is a money maker. Don't just sit and expect people to wait on you for 5 hours while you sip coffee when that 5 hour period could have produced a 100 dollars in tips for the waiter alone, not even considering the amount of money you're burning on their dime in return. It costs money to turn on the lights, heat the place to comfortable in these conditions with the front door constantly opening, and have everything on the menu ready for you on a whim. If the lights are on the grill is hot and the taps are pressurized and that costs a lot of money too. The trick to making money in that game is fast happy turnover of customers. A seat is the real estate. Don't park your big rig in front of it and block it up on sale day.

ASK FIRST.

Find a slow bar and tip egregiously well because someone is going to feel they need to make sure you're well taken care of the whole time you're doing it, so regardless if you order or not that deserves payment.