Unless, of course, this is Starbucks' MVP and they are figuring out the parameters of coffee delivery. Now that would be brilliant.
Some suggestions:
* target businesses. Your orders will be larger, evenly scheduled and the customers are less price sensitive. Expect tough competition, though, unless ...
* Broaden/specialize your product range. I assume you've chosen Starbucks because of the brand recognition. But what if you offered spectacular coffee from local coffee shops (assumption: Starbucks produces average coffee)? This could be one of your USPs: great coffee from local baristas delivered to the doorsteps of your customers.
* Transportation makes or breaks any type of delivery service. You need a form of transportation that's dirt cheap (no gas), small yet can carry many cups of coffee. I'm thinking a bike designed for cargo, maybe something like [1] ?
* Vacuum flasks may solve some of your issues. Why not carry around a couple of these and pour the coffee when you reach your destination? Naturally this would have some implications on branding and product range.
[1] http://www.treehugger.com/bikes/bicycle-cargo-chapter-1-rack... http://www.treehugger.com/bikes/bicycle-cargo-chapter-2-bike... http://www.treehugger.com/bikes/bicycle-cargo-chapter-4-carg...
They get insanely high gas mileage.
Of course, you can treat this as an educational experience to learn more about what you need to consider for these types of businesses going forward. Just realize that proving you can sell a product at a low but unsustainable price point does not prove the product is viable.