I wonder why there isn't a "Buy now" button, they're already charging your credit card, they'd just need to hire someone to run the item from inside the store to you at your car. Add some sensors like body temperature monitoring; Sweating person who looks like they like their sweets? "5% off this ice cream if you hit 'Buy!' within the next 30 seconds!".

Damn, I think this is an idea. At least for developing countries, were labor is cheap, the runner is the expensive part of this concept.