Doesn't matter how i look at it...

I pay $100, you give me $70 worth of ALT's and $10 back (why??? You could have asked for $90 instead)
So, you make $20

Next month, same deal but i only pay $90...
So, you make $10

That's $130 in 12 months... Defenatly a win for you... But where's the added value for me? I can just use binance, or etherdelta, or bisq, or openbazaar,... And if i use those, i'll get the coins or tokens I want, and it'll cost me less than $130 in fees.

I just fail to see the added value...

I don't see how your "compounding" mechanism would add profit for me (just for you), i don't see why you'd ask $100 and just give $10 back at the end of the month.

Maybe there's a language barrier between us, but i really don't get this service.