The maintenance problem.
THE PROBLEM
Unmaintained client sites get compromised. That becomes your problem: cleanup, other accounts affected, and reputation damage.
Whose responsibility it was matters less than who deals with it.
THE OPTIONS
Sell maintenance as a service, and do it State clearly that updates are the client's responsibility Both, with a stated position for those who decline
WHY SELLING IT IS BETTER
It aligns the incentive. You are paid to prevent the thing that costs you most.
It is also recurring revenue for predictable work.
WHAT MAINTENANCE INCLUDES
Core, theme and plugin updates Backup verification Uptime monitoring A security scan A stated amount of small changes
DOING IT EFFICIENTLY
A consistent routine applied to every site, on a schedule.
Back up, update, check the site loads, check a form.
FOR CLIENTS WHO DECLINE
State in writing that they are responsible, and what happens if their site is compromised.
That protects you and sets the expectation.
THE UNMAINTAINED SITE
Eventually it will be compromised. Plan for that rather than hoping.