text: what are legacy data and what are the options for their incorporation into an e-commerce system?   you need to search all of that and its not easy question for an ordinary person. it's either theory or a real practical concept. but i have another qustion for you because i think you are a head of me in e-commerce. what is switching cost and transaction cost? are they different from each other or show me their similarities. e-mail me if you have the answer please: jasonafg@yahoo.com