Ah,
Just checked through the coins and tokens available, seems you have quite a few solid projects, e.g. LatiumX and OriginTrail.
Do you obtain a store of tokens directly from the projects, since I noticed a few times you said certain tokens were out of stock?
Indeed, they do. I'm also a holder of LatiumX, OriginalTrail, ClearPoll.

Their whitepaper actually sums their system pretty well.
For liquidity, if they dont have a token in stock they mimic orders on exchanges.
Also users assume they only have 1 wallet and if that wallet doesnt have a token in it then they cant fulfil the order. That isn't the case though.
They have 5+ wallets and they are able to fill nearly every order and refunds are only done if absolutely necessary.