When using any sort of record for genealogical research, ask yourself–who gets in this record? Is it just landowners? Is it everyone who was alive in a certain place on a certain date? Is it just men of a certain age? Is it anyone who dies in a certain location? Is it just people who can vote? Is it people who have sufficient assets? Is it members in good-standing of a certain denomination?
How people get into a record matters when you are interpreting the information you find in that record and how you go forward when someone is not located in that record.