So speaking about the supply you will actually provide the tokens as and when required by the user and you also not mentioned how you will circulate them? Like with exchanger or by the marketplace checkout itself? Thats going to be centralised I guess.
We will ICO the tokens to investors, and people wishing to buy from someone on our marketplace, will need to buy the tokens via a public exchange (say shapeshift or someone like that). They're not buying the tokens from us. To reduce customer friction, we may provide an interface to a public exchange that exchanges fiat for tokens, but these tokens are purchased exclusively from a public exchange.