NuShares and NuBits are part of the same blockchain. NuShares can be minted with, (like Peercoin) while NuBits cannot be minted with. This means that users of NuBits need not worry themselves about helping to secure the blockchain. It’s already taken care of for them by NuShareholders.
By minting their NuShares and working to keep the USD peg, NuShareholders are basically providing a stable, decentralized crypto transaction service for users of NuBits. The question is how are NuShareholders being compensated for providing this service? There needs to be compensation, otherwise there is no incentive for NuShareholders to keep providing this service.
As @Nagalim mentioned above, one of our upcoming features is volume dependent transaction fees. According to coinmarketcap, we currently have a supply of over 700k NuBits. When volume dependent transaction fees are added to the protocol, these NuBits will slowly be burned away as people make transactions on our network. As the supply of NuBits is decreased through transaction fees, shareholders will need to keep printing and selling more NuBits to replace the ones that were destroyed. So NuShareholders provide a service and users of NuBits are charged for that service through our network transaction fees. NuBits destroyed through fees is profit for shareholders, because we get to create more and sell them again.
Nu does have costs to continue running. These costs take the form of our entire liquidity providing operation to help maintain the peg, plus development and marketing costs. In order for Nu to be financially successful, we need more people to start using NuBits, because our profit is tied to the number of daily transactions being made on our network. The more transactions made, the more NuBits destroyed through fees, the more we can sell again in the future.
Many shareholders are very long-term minded when it comes to the financial success of our network. We realize it will take a while for this technology to take off, so in the meantime we are working toward improving all aspects of the network, especially our liquidity operations. We are also working on a decentralized exchange called B&C Exchange, which will help move crypto trading off of centralized exchanges and increase demand for NuBits, as it will be used on B&C as a substitute for fiat. Ultimately, the goal is to have people using NuBits as a day to day transactional currency, rather than only using it to hedge Bitcoin volatility like its being used for right now.