you should check out lykke's whitepaper and what they are building - funded
maybe lykke's exchange only promote can free fee trade
ussualy new exchanger alwyas promote use trading without fee, or very low fee
This is true, some of the new exchanger since they are new in this industry, they will do everything to invite the community to trade in their exchange, because that's the main purpose of their business. And most of it they will free coins, and the lowest percentage fee for the transaction.
A Multisig Example
You hold 100 Lykke coins (LKK) in your wallet. You want to exchange for euros on the Lykke platform. You hold the private key to your coins in your wallet (it’s the 12 words you wrote down when you originally set up your wallet).
At the same time, the Lykke exchange holds a second private key that is tied to your Lykke coins.
The same is true for your counterparty, who wants to trade Euros for Lykke coins. All coins on the Lykke exchange have two keys: one for the owner, and one for the exchange.
The coins exist right now on the Bitcoin blockchain. The goal of this transaction is to transfer the coins from one bitcoin address to another.
Now, the trade requires four keys: one from each owner, and one key from the exchange for each token. When all four trades are present, the bitcoin blockchain accepts the trade.
It takes just a few minutes to settle, and generally around 30 to 60 minutes for a full confirmation.
The Refund Contract
What happens if something bad happens to the exchange? For example, hackers get the password and are able to discover a bunch of private keys. Two things:
1. The hackers can’t move any coins, as they require you to agree as part of the multisig transaction. So the private keys are useless to the hackers.
2. If the hackers somehow take the exchange down, destroy the keys, or hold them for ransom, a special refund contract unwinds the trade. Let’s see how that works. Assume the Lykke keys are gone:
First, you can’t trade. Your assets are stuck in your Lykke wallet. Since you registered with your email address, you will get a notice saying Lykke’s private keys have been compromised.
A special contract on the blockchain checks for the private keys every day. If it sees the keys, it resets. If it doesn’t see the keys, it keeps checking for 30 days. If, after 30 days, it still doesn’t see the keys, it automatically issues a refund. In your Lykke wallet, there’s a place in the settings page where you can give a bitcoin refund address. You can do that now, or you can wait and do it if you ever need to (we hope you never do). The refund sends all your bitcoins to that address, which you have the sole private key to — this address is off the exchange.
At the moment, this only works for bitcoins. We will soon announce the refund feature for all colored coins as well.
https://medium.com/@pullnews/the-lykke-platform-9bc2b7785da2#.dall7e9m6