Setting up that business might be easy but getting it running profitably would be the challenge. You would be competing with big players with huge funds and a big client base. For you to take a slice of the exchange pie would mean having to find innovative ways to attract potential clients. Also, try not be to a business that deals solely with exchanging. Add other services that people are looking for just so you would have an edge over your competitors. Once you've figure things out, promos and giveaways every now and then wouldn't hurt your chances of making it a profitable business that can run for a long time.