Mansion are not charging commission on exchange bets so basically there is no profit. Its common practice for new exchanges to support their own markets, incuring small losses on bets, but they do add up over a year. Although they may have paid for the software etc, it costs a small fortune to run and keep updated , add the cost of back-up to ensure smooth operations at all times and staff, office space, advertising, it doesnt take long to see a loss balloon.
All this will of course have been foreseen and budgeted for, with an ample time-scale for the losses. My worry would be under estimating those losses, Friends working at both Betfair and Betdaq are constantly talking about huge costs, especially on the computing side.
BETDAQ believes that security is paramount. All customer funds are held in ring-fenced accounts and are further secured by a US$ 10 million bond which has been placed with Allied Irish Banks plc.
As usual, you pays your money and takes your chances.