When you purchase a bottled or canned drink in Germany, you typically have to pay a deposit (Pfand). You can tell this by whether or not the label has this symbol on it.
Then, you can bring all of your empty drinks back to the grocery store, put them into a nice machine at the front, and it will spit out a coupon. Give this coupon to the cashier, and they will either give you your money back, or simply take it off of your grocery bill.
For the soft plastic bottles that can only be used once (Einweg), this deposit is 25 cents. For hard plastic and glass bottles that are sterilized and used again (Mehrweg), this is 8 or 15 cents.
For the shocked Americans reading that statement: Yes, glass and plastic bottles are cleaned and reused over and over again. I have read that the average beer bottle is reused 15 times.
Anyways, I really love the whole deposit system. It is a great way to get people to recycle, and it always feels like you are getting free money when you bring your bottles back to the store. The problem is that Marco likes to reuse the 1 Liter plastic bottles at work. So, when I visited his office the other day, I saw this bottle on his desk.
So, we brought this bottle to the grocery store that evening, and sure enough, the damn machine would not take it.
Luckily, you can just give the bottle directly to the cashier, but this is not nearly as efficient. At least we got our 25 cents back, though.