Net revenue retention
Net revenue retention is this period's revenue from clients who were already clients last period, divided by what those same clients paid then, with expansions and downgrades both counted. Above 100% the existing book grew faster than churn removed it, so the agency would grow with no new business at all.
Net retention can read well while gross retention is poor, when a few accounts expanding hide several leaving. Read the two side by side, because the gap between them is how much of your growth depends on a handful of clients.
For a retainer agency the expansion side usually means scope added at a fee, so net retention is also a check on whether scope growth is being invoiced or absorbed.
Covered in depth
Agency client churn rate benchmark: what is normal, what is a warning, and which churn you should be causing on purposeRelated terms
Not sure which of these is capping you?
Six questions, two minutes, and the diagnostic names the one constraint worth working on first.