C'mon dude! Harden up! I'd say in that situation, go for the instant date! If you can't get that, then at least settle for the number. Ideally though you want to sense her wanting the number. You know then that you've done your manly job and created interest. Even better, get her to ask for your number! Much less chance then of the dreaded flake! But then if you are getting enough numbers and dates, who cares if a few of them flake. It's only when you have nothing else going on, that the flake really sucks.