Ground rules
More usefully, simply as important, this is maintenance work, and maintenance work only fails when it stops.
Put plainly, handled steadily, local landing pages stop being a project and become a habit.
Drift Directory
Record the canonical version of the website field somewhere the person on reception can find it. The businesses that win here are not the loudest, only the most consistent.
Which Sources Are Worth the Time?
Keep a change log; six months on, no one remembers which field was edited or why. Comparisons between competitors tend to suggest clean-up work pays back fastest for trade contractors.
How Frequently Should the Data Be Checked?
The finish line is not perfection; it is a profile that no one has to argue with, once the obvious errors are gone. Across a large enough sample, the correlation between unambiguous data and review velocity is hard to dismiss.
Where Should the Clean-Up Start?
Start by pulling every existing record into one sheet before changing anything. The pattern across audits is that the majority of profiles carry at least one contradiction.