The busiest season is not when anybody is choosing
Filing deadlines dominate the calendar and the decision to change firms happens somewhere else entirely.
A business owner considering a new accountant is usually reacting to something: a return that went wrong, advice that never arrived, a business that outgrew the arrangement, or a growth decision they need help with.
Almost none of that happens in the weeks before a deadline, when everybody is heads-down and nobody has the appetite for a transition.
The searching that matters therefore clusters in the quieter months, which are exactly the months when a firm's marketing usually stops because everybody is recovering.
There is a smaller peak immediately after a filing season, when a bad experience is fresh. A firm that is visible in that window catches people at the moment they have decided to change.
The practical consequence is that content should be built and ranking well before the busy period, and the outreach should be planned for after it rather than during it.