Interesting article about the implications of making your own latte using a double espresso and free milk at Starbucks - does the "twisting" of freely-provided resources for a purpose other than "intended" break any kind of limit? (Link via Richard Veryard.)
Quality and convenience aside (i.e. you may save money, but need the time and the skill to get the same quality..?), I can see Starbucks getting pissed off if everyone started doing this. Why? Simply because products these days are not just a simple trade of money-for-goods. Products are wrapped up, instead, in a whole context of brand and whatnot, that intends to turn them form product into experience.
By twisting the product, you're also twisting that experience, and the entire idea of "service" that is supposed to be "on sale". As per Disneyland, the "product" is the world you walk into once you're through the doors - the ambience, the staff, the banners, etc. Also - importantly - this includes other clientel. Hence, just as nightclubs turn people away for being dressed wrong, I can see chainbrands getting huffy about people behaving in a way that doesn't fit their "here to serve" image.
But maybe I'm just too cynical...? Will check for some follow-up articles, as it was a few weeks ago now...
Addendum: Starbuck's position is quoted in the original article as:
Customization is a fundamental attribute of the Starbucks Experience. We provide condiments to our customers so they can make their drinks to their liking and we appreciate their patronage. We trust our customers to make the choices that are right for them.
Well, I was right that it's an "Experience" (ooh, capital 'E' too), but they don't seem too put out by it. Maybe they're smarter than I give them credit for ;)