Both charge a fee for the service, it's just that since you're hungry and don't need to wait a few to five days for your PayPal money to hit your checking account, they'll get you your pizza tonight. If you're selling services, how is it possible to package the requirements up so that you can fully describe what the client is buying in an assured way? This is also important so a person can offer a flat price that can potentially be programmed into web site instead of hourly rate that will nee...