This is always an excellent idea when an ancestor has been located in a census record as relatives could always appear on the page before or after your ancestor. At the very least you may see names you recognize from other documents on your relative, perhaps as witnesses or bondsmen.
If you locate a deed, view the ones recorded before and after as well. Sometimes deeds were recorded in groups and several might have been filed successively.
This may be helpful in court and other records as well.
Usually not helpful with birth records unless there were twins!
And deaths are another story.