I’m currently traveling around Riga, Latvia and one day I ended up at a weekly outdoor music venue. Like most outdoor festival type events there were vendors of all kinds including food and drink of course.
Now typically when one buys a drink, it is given in a plastic cup which is usually disposed of quite quickly. This leads to a lot of waste and a lot of cleanup as the cups tend to end up thrown about wherever.
But at the Kalncielma kvartāls event I was told by the vendor that it works differently. The beer was €3.50 but I needed to give a €1.50 deposit for the glass. When I was done drinking, I would get my deposit back.
This is reminiscent of the shopping cart system all over Europe. To get a cart you need to put a €1 coin into the cart and when you bring the cart back, you get the coin back.
This is very intelligent because it ensures that the patrons do the work of cleaning. If the glass is never returned, the vendor makes an extra €1.50. If the glass is broken, then the costs are covered. And the returned glass can get washed and can immediately be put back to use with no extra work necessary on the vendors part.
People are also much more likely to hold themselves responsible if there is a “deposit” involved. Even something as small as a €1 coin.