I'm terribly sorry. But your continued use of "pyramid scheme" is just wrong.
1) "they expect users to hold an ever-increasing amount of their currency in their accounts and not spend it immediately."
> Where does it say that ? Unfortunately no where. And who wants to hold their currency ? Use case: I want a new phone. I accept the offer from swapidy for X currency and then buy a new iphone at X currency. At what point do I want to hold my currency ? No, I want a new phone and if their pricing makes sense I transact. Thats it.
2) "too many users tried to spend their currency all at once they would go out of business and you would lose your money;"
> At what point would you loose your money ? The currency is valid and you can purchase an item. They send you that item. I am assuming your inference is that they do not stock any of the items they sell and I am unclear where you draw that inference from ? Please let me know if you have some sort of information that I do not other than what is illustrated on the site. If you transact and sell your phone, you send it to them and I assume they will subsequently sell that. You purchase a new phone and they send you that new phone. There is obviously the requirement for inventory and stock and so on. Thats a business and cost inventory issue, nothing else. If the company fails, you become a creditor - like when any company fails. It's a trust issue and up to them to ensure that its trust worthy.
3) "it's a pyramid scheme."
> No, its not. Refer above and please refer to Wikipedia or other sources to learn about pyramid schemes.
4) " They give you $440 instead of $400 for your iPhone, but then a new product that would cost $400 on Amazon costs $440 in their currency. It's not a real discount. "
> Amazon is not a fluctuating pricing market like ebay or other such services. You will receive a standardized cost on Amazon for a extended period of time whereas this site infers you will receive the current daily market rate or close enough. This is the difference and therefore ultimately the difference in the pricing mechanism. If you want cash, transact at some other market and see if the pricing differential is more advantageous than what they offer. Some items will be cheaper and some will not be - don't tell me they actually want to run a site that makes money ? The use of virtual currency is to lock a user into their service and there is nothing wrong with that if you want to accept their buy offer which is more than you would receive elsewhere. No one is forcing your hand to transact.
5) "They take less as profit than Amazon"
> How do you know what profit they take ? Feel free to let me know.