Version 0.1 · open development
An open dictionary of definitions, formulas, units, and limitations for two-sided-platform metrics.
A single metric rarely answers a question on its own. The diagnostic chain and selection rules are set out in the Marketplace metrics; their application to the balance between sides is covered in Marketplace liquidity.
The share of eligible buyers with an initial qualified success in a baseline cohort who achieve at least one subsequent qualified success within the defined repeat window.
buyers_with_subsequent_success / eligible_buyers_with_initial_success × 100%
The share of a buyer cohort completing at least one transaction in each subsequent observation period, reported as a retention curve across periods rather than a single number.
buyers_active_in_period_n / buyers_in_cohort × 100%, for n = 1, 2, 3 …
The share of confirmed interactions or transactions cancelled before a pre-defined successful-completion event within a stated window.
cancelled_confirmed_outcomes / confirmed_outcomes × 100%
The observed distribution of intervals between consecutive completed transactions by the same demand-side participant within a micro-market, published as a median and percentiles rather than as an average number of purchases per calendar period.
distribution(timestamp_of_transaction_n − timestamp_of_transaction_n−1) across demand participants in the micro-market, retaining censored intervals
The share of all qualified exposure captured by the top decile of eligible supply units, ranked by the exposure they received during the observation window.
qualified_exposure_of_top_decile_supply / total_qualified_exposure × 100%
The share of eligible supply units receiving a preregistered minimum amount of qualified exposure or candidate-set inclusion within the observation window.
eligible_supply_meeting_exposure_floor / eligible_supply × 100%
The share of eligible transactions, started or confirmed under a preregistered rule, that reach a classified failure state instead of the intended successful outcome within the observation window.
failed_eligible_transactions / eligible_started_transactions × 100%
The share of eligible demand units for which available supply satisfies a pre-defined successful-outcome criterion within a specified window.
matched_eligible_demand / eligible_demand × 100%
A construct rather than a single measure: the degree to which a supply unit gives a demand participant sufficient and accurate information to decide. It is measured through a declared model of observable completeness, accuracy, and freshness indicators, published separately.
no single formula exists; the published output is a vector of indicators — required-attribute completeness, share of discrepancies with the actual item, price and availability freshness, and moderation-edit share
The number of simultaneously active eligible participants on each side within one micro-market during the observation window, reported as a pair of supply and demand counts rather than a single summary figure.
(active_eligible_supply_units_in_window, active_eligible_demand_participants_in_window) per micro-market
A construct rather than a single measure: the degree to which a realised match satisfied the original need of both sides. It is measured through a declared model of several observable indicators, published together and separately.
no single formula exists; the published output is a vector of measurement-model indicators — completion rate, refund rate, dispute rate, repeat engagement with the same counterparty, and deviation from the original request
The share of payment attempts on confirmed interactions that ended in a decline or technical failure and produced no successful capture within the attempt window.
failed_payment_attempts / total_payment_attempts × 100%
The share of supply units that received qualified exposure and then attracted at least one demand-side response meeting a preregistered qualification rule within the window.
exposed_supply_with_qualified_response / exposed_supply × 100%
The share of completed transactions that were refunded in full or in part within a preregistered window.
completed_transactions_with_refund / completed_transactions × 100%
The share of eligible new sellers that reach a pre-defined useful-participation event within a stated window after cohort entry.
new_sellers_reaching_activation_event / eligible_new_sellers × 100%
The share of eligible sellers with an initial qualified success in a baseline cohort who achieve at least one subsequent qualified success within the defined repeat window.
sellers_with_subsequent_success / eligible_sellers_with_initial_success × 100%
The share of a seller cohort that maintained available eligible supply or completed a transaction in each subsequent observation period, reported as a retention curve across periods.
sellers_active_in_period_n / sellers_in_cohort × 100%, for n = 1, 2, 3 …
The ratio of eligible supply units to qualified demand units within the same preregistered opportunity unit: a micro-market and observation window.
eligible_supply_units / qualified_demand_units
The elapsed time from a seller entering the cohort to the moment they first create a supply unit that passes eligibility rules and becomes available for matching.
median(timestamp_of_first_eligible_unit − timestamp_of_cohort_entry) per cohort, with censored observations retained explicitly
Elapsed time from a defined eligible participant or supply unit entering a cohort to its first transaction that reaches the specified terminal success event.
first_successful_transaction_at - eligibility_started_at; report median, quantiles, and the no-event share
The duration between an eligible demand unit becoming available for matching and its first match that satisfies a pre-defined criterion.
matched_at - eligible_demand_at; report median and quantiles
The share of confirmed interactions that reach a preregistered successful completion event within the defined fulfilment window.
completed_outcomes / confirmed_outcomes × 100%
The share of eligible supply units that receive no qualified demand signal or valid match within a stated observation window.
eligible_supply_without_qualified_demand / eligible_supply × 100%
The share of eligible demand units that do not reach a pre-defined successful outcome before a stated observation window ends.
eligible_demand_without_success / eligible_demand × 100%
The share of eligible supply units that received no qualified exposure and no candidate-set inclusion during the observation window.
eligible_supply_with_zero_qualified_exposure / eligible_supply × 100%