The key ingredient for 1-on-1 marketing is data. If you want to create 1-on-1 marketing, you need to know from every individual who they are, what their interest is and what they like/prefer. Without accessible data this is not possible and you can never create an intelligence 1-on-1 marketing strategy.
The first step in this regard is to make sure all possible first-party data is reachable and being synced to the systems with which you work. A next step is to set up different accessible feeds where from dynamic creatives are being built. You can have uncountable offers for your customers and you want your customers to always see the most suitable offer.