If the trend in storage pricing continues, Dropbox would be unable to charge anything at all for any of their plans within a few years. So instead of lowering prices they increase storage, which is a fairly safe thing for them to do, because people only use the space they need.
Evaporated milk is exposed to high heat to reduce its water content and then preserved in a can. Pumpkin pie recipes sometimes require evaporated milk. Evaporated milk can be used to make fudge.
Water can be added to evaporated milk to again make regular milk, but it is more often used for cooking (think pumpkin pie) than drinking. The shelf life of evaporated milk is influenced mostly by the best before date and how it is stored. So, in fact evaporated milk does go bad.