Expansion Saturation
The share of customers who have already expanded — a gauge of how much up-tier runway is left.
What is it?
Expansion Saturation is the share of paying customers who have expanded at least once. It tells you how much of your base has already taken the up-tier step — and, by implication, how much runway is left.
It is a runway gauge. Early on, a low saturation means most of your expansion potential is untapped; as it climbs, each additional dollar of expansion gets harder to find, which reshapes where future growth must come from.
How to calculate?
Divide the number of paying customers with at least one expansion event by the total number of paying customers. Forty percent means two in five have expanded. Decide whether a customer who expanded and later contracted still counts, and apply that rule consistently.
Read it beside expansion rate: the rate tells you how many are expanding now, saturation tells you how many are left to expand at all.