It's going to be an exchange to compete with those made for trading. Although everything is still in the planning stage wetsuit said he intended it to .be an alternative to something like Shapeshift. Just the ability to switch from one coin to the other. The advantage will be for small amounts you will not have the hefty withdrawal fees that most exchanges charge.
It would be quite nice if it was similar to shapeshift, maybe offer people a chance to make buy/sell orders before transactions go through mihgt reduce the charge to you in case a coin immediately drops by 50% or something.
As I've seen, if you charge something between 0.02-0.5% then it's not too much different to the value of the buy/sell orders as there's just a usual fluctuation between exchanges that could add that rate - unless you get a really high volume.