This reply will probably go Off-topic. Again, this is just brainstorming.
Freemium Storage Model
When a user wants to increase their NSL (Network Storage Limit) they pay Safecoin to the Network, where it is recycled. Let’s say, you create an account with NSL 100Gb (free) by default. If you want to store 150Gb of data, you will need to pay Safecoin to increase your NSL to 150Gb. Now you can PUT 150Gb of data onto the Network. Hopefully, this explains why someone would pay for premium storage.
Some people will make multiple accounts to take advantage of the free storage. We had big discussions on this here Network Storage Limit VS Network Reserve and here Proof of unique human.
Consumption Model
This alternative model does not charge for PUT. Instead, the NSL is determined by (available_space + free amount). If you want to increase your NSL, you’ll have to dedicate more hard drive space. Technically, it’s an unenforceable limit, if data is not deleted. This might be the reason why we opted to use Safecoin payment for PUT instead.
My goal is to deter users from storing more data than they are supporting. If we consider the loss of Safecoin earning potential, and de-duplication… a DOS attack (over capacity) becomes less likely. It is not a perfect solution though. We talk about it here DOS Attack caused by Data Overload.
I am interested to hear your ideas on a consumption model.