- Formula
- % of cohort active (transacting) in month N
- Unit
- %
- Models
- Marketplace
No public benchmark exists for this metric yet. This is where Omega Point's proprietary data will fill in.
What it is
Buyer/seller retention cohorts track the share of a cohort that remains active — defined as completing at least one transaction — in each subsequent month after their first transaction. Formula: % of cohort active (transacting) in month N, tracked separately for buyers and sellers.
How to calculate it
Group users by their first-transaction month to form cohorts. For each subsequent month N, count the number of cohort members who completed at least one transaction and divide by the original cohort size. Plot this as a retention curve for buyers and, separately, for sellers. Stabilization of the curve (a "flattening" at some retained fraction) indicates a loyal core; a curve that continues declining toward zero suggests weak network effects or high substitutability.
Why it matters
In a two-sided marketplace, buyer and seller retention cohorts are the clearest signal of network-effect strength. If buyers keep returning and sellers remain active, the market is self-reinforcing. If one side churns while the other doesn't, supply-demand imbalance is likely. Cohort curves also reveal whether newer cohorts retain better than older ones — a key signal that product improvements are compounding over time. This makes the metric a direct proof point for the marketplace's defensibility thesis.
How to read it
There is no established public benchmark for buyer/seller retention cohorts in marketplace businesses. Retention curves vary so dramatically by category, purchase frequency, and price point — a daily food delivery app versus an annual B2B services marketplace — that a cross-company absolute band would be meaningless. The notes accompanying this metric explicitly flag this: the quantified version of marketplace retention is GMV retention, which carries more cross-company comparability.
Because no defensible estimate can be offered here, the right comparison is your own cohort trend over time: are newer cohorts retaining better at month 3, 6, and 12 than older cohorts did? Is the curve flattening sooner? Is buyer retention correlated with seller supply depth? These internal comparisons are more informative than any number we could responsibly propose.