The unit is a day and it leaks. A call here, a review of a document there, and a project sold as five days consumes seven, which is invisible until the year's utilisation is calculated.
Advice that nobody acts on looks like failure. Tracking which recommendations were implemented, by whom and when is what allows a consultant to show that the unchanged results belong to the unimplemented list.
Credentials accumulate dangerously. Analytics, search console and content system access for dozens of clients is a security liability, and removing it when an engagement ends is a step almost everybody forgets.
There is no monthly floor. Work ends by design, so a record of who was helped, when and what remains outstanding is the only pipeline a consultant has, and a quiet month begins three months before it is noticed.