I have been away for a few days to visit a friend and he gave me back my copy of A Definitive Guide to Betting Exchanges. This book is a very good introduction to Betting Exchanges although it may be a little bit dated now. I found the section about tennis very informative as I had little knowledge about these markets.
My favourite section is the one that lists all the strange things that have happened on exchanges. The best of these is the time a lady placed a 500 bet @1.01 to back a favourite that was cruising to victory in a hurdles race in Ireland. The bet was placed just as the horse was approaching a hurdle on her pictures (At the Races). Now as you probably know if you have SIS or are at the actual race course you have a perceived advantage. Someone with this "advantage" saw the horse make a mistake and the price shot out to 95. Next thing to happen was Ruby Walsh clung on and made a miraculous recovery and the horse promptly went on to canter home netting the lucky punter a £47000 profit when she was hoping to make£5. So just remember the guys with fast pictures don't always win.