Overwriting or Creating a New Customer Profile
When you are typing in the customer name, you will notice that a drop down will appear showing you other customers in your address book that closely match what you are typing. If you select one of these customers, the information from that customer will be manually entered. The system is assuming that you will be working with that customer profile, and that any changes made to the customer information on the leads page, should overwrite and update the customer profile in your address book. If you would like to force the software to create a new customer record, do not select the pre-entered information.
Customer information is not saved directly to a lead. Instead, it is saved to your customer address book and is used as a reference to that customer information that is saved to your leads. So, if you make a change to a customer profile, every lead that has that customer referenced, will immediately display that new customer information.