Same goes for me. At current state I always try to find free wifi spots, because data-bundles are still a bit expensive in Germany.

Also thinking about the possibility you have for example as an exchange student in a foreigne country. You don't want to make a mobile phone contract sometimes because it is expensive to get out of it when you are leaving the country again. Also it is sometimes expensive as hell if you have mobile data options.

This is the perfect solution.