How we count the marketplace
Every figure we publish comes from one place — the MythicLemon Marketplace Index — and we'd rather tell you exactly where our numbers stop than imply we know more than we do.
What the Index is
The MythicLemon Marketplace Index is our own continuously compiled dataset of the Unreal Engine asset marketplace. It tracks the catalogue — every listing, its category, price, supported engine versions and the buyer activity attached to it — and we recompute each report, dashboard and insight directly from it rather than sampling or estimating.
When we cite a share or a median, it is a real calculation over the dataset for the period in question. Nothing on this site is a projection unless it explicitly says so.
As-of reporting
The monthly report is built “as of” each month-end: it reconstructs what the marketplace looked like at that point in time — the listings that existed then, the prices in effect then, and the buyer activity recorded up to then. A dated edition is an analysis of a past moment computed now; it was not published back then, and we don't pretend it was.
Where our coverage stops
Coverage windows
Catalogue, pricing & engine data is complete through May 2026. The most recent month is partial and firms up in a later revision.
Buyer activity — questions, reviews and ratings — is complete through September 2024. Any figure that depends on it is stamped accordingly and shown unchanged for later periods; we never extrapolate it forward.
This matters most for one trap we take care to avoid: a brand-new listing has had little time to attract questions or reviews, so counting recent arrivals as “failures” would be wrong. Where we measure engagement over a product's life, we only include cohorts old enough to have had a fair chance — and we say so on the chart.
Rules we hold ourselves to
- ✓No invented revenue. The marketplace doesn't publish unit sales, so we never sum list prices into “revenue.” Where we need a demand proxy, we use buyer questions per listing — a far better signal than a star rating.
- ✓No extrapolation. We don't fill gaps with guesses. If we haven't measured a period, we don't chart it.
- ✓Every figure is downloadable. Each chart carries the data behind it as a CSV and its own coverage stamp, so you can check our working.
- ✓Counted, not sampled. Figures are computed over the whole dataset for the period, not a sample.
Reuse
Our published figures and the CSVs attached to each chart are available under a Creative Commons Attribution 4.0 licence. Use them, chart them, cite them — a link back to MythicLemon is all we ask.