Weekly: status, and the signals nobody logs
The status call is delivery. What matters for retention is what the account manager notices around it: who attended, how fast the last approval came back, whether anything was escalated and left open. Thirty seconds of logging after the call is what makes the pattern visible three months later.
Monthly: the report, discussed rather than sent
A report emailed is an artefact. A report walked through is a relationship event. The discipline worth enforcing is that every monthly report has a conversation attached, with a named attendee list, and that the agency names the disappointing number first. Clients forgive underperformance explained far more readily than underperformance discovered.
Quarterly: direction, not numbers
The quarterly review should answer one question: are we working on the right things for what you are being measured on this year. Results, spend, scope delivered and escalations are the evidence, not the agenda. This is also the natural moment to raise scope drift and expansion, because both are easier to discuss in a planning meeting than in a renewal one.
Quarterly ahead of the end date: the renewal runway
Three months out, the renewal becomes an owned task with a plan. What changed this year, what the client needs next year, what the scope and fee should be, and who internally has to approve it. Agencies that do this consistently find that a large share of renewals are settled before the formal date arrives.