Meeting customers' expectations comes down to multiple good performances. Every touchpoint contributes to the customer's feeling, so every touchpoint has to be on point. Make your touchpoints outstanding with the use of data you already know about the customer.
Personalizing the customer journey creates a unique feeling for the customer. To be able to do this you really need to use all the information you have at hand. Each touchpoint generates data that you need to keep careful track of. But data that does not come from touchpoints is also extremely important.
But you are not there by simply using all the information. To offer a personalized customer journey, you obviously need to link all the information to the right person. You really need to have a complete picture or profile of a person to offer them a customized experience.