There are a number of different reasons data would be received differently from person to person. Data collection is fluid making it complex, but lets cover a few basics.
Reasons why some people have more data than others:
- What information is available differs from person-to-person
- Head of house hold data verses individual
- Server reassignment
- Using a computer at work vs at home
- Visitor could be using a VPN
- Limited data for that person
With +Person:
First Name, Last Name and Email Address is a successful identification. Everything else is enriched data.