I think you have misunderstood the model. There's no need to pre-buy. Incent are bought as required off the open market. And there's no limit to how many users the platform can support.
When a user joins Incent, and adds their bank account, the platform purchases Incent on their behalf everytime they spend any amount anywhere. Incent, the company, pays for this Incent 'as required off the open market'. Is this correct?