Welcome to the forum @Predator,
This is an old concept and is no longer being used.
Safecoin is used whenever you store data on the network and the network no longer uses you supplying space to pay for your storage of data. Your thought here is one reason it was changed 
Thus when you store your files there is some (portion) of safecoin used to store the data.
If you decide to farm (supply disk space) then you become a node on the network with a (data storage) vault on your hard drive. When you retrieve chunks then you will be also be earning safe coin.
There is a primer for the safe network that should help to answer any basic questions you may have. It is a very good read