This is how German beer and much else works. Most beer, milk and bottled water is sold in one of about ten shapes of bottle. Four kinds for milk (two sizes two colours), one for water, three for beer, some lesser used that I've forgotten right now, and IIRC the market percentage for these things is 65% at the moment.

I'm sure someone will follow up to explain how horrible the situation is and all about those other 35%, but compared to the US or India it's pretty good.