I think what he’s talking about is sharing some of his local free space with Storj… to have it pay for his bill of also using Storj for Cloud Storage. In very rough numbers for every 2.5-3TB that gets filled by Storj data… it pays for you to use 1TB of data yourself.
A lot of people want some offsite storage, for backups and such. Since they already have too much local free space… they can share that space to pay for their Cloud Storage bill. It’s a pretty sweet setup!