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.
If you open a can of evaporated milk, it will spoil (separate and become rancid) just as quickly as if it were whole, undiluted milk. To reconstitute evaporated milk, you would just add a like quantity of water...in other words, 4 ounces of evap plus 4 ounces of water equals 8 ounces (1 cup) of regular milk. In the case of condensed milk, you wouldn't necessarily know the concentration, so you can't know how to reconstitute it precisely.