Turning search placement into an estimate of units
Wayfair never publishes unit sales. But cumulative review count is displayed on every listing, and the change in that count over a week is a direct function of how many people bought. Weekly snapshots convert a static number into a flow — and that flow, read against rank, is the relationship between placement and sales volume.
The measured visibility gradient
Median cumulative reviews by organic rank band, indexed to the page-2 band. This is the empirical relationship the velocity model is calibrated on.
Estimated weekly units by rank band
Mean estimated units per SKU per week, derived from weekly review deltas at a 3% review rate. These rows come from the illustrative panel — the shape is calibrated on real data, but the levels become measured once collection has run for four weeks.
Mean new reviews per SKU per week
The measured signal underneath the unit estimate
Estimated units per SKU per week
new_reviews ÷ 3% review rate
| Rank band | SKUs | Median new reviews/wk | Mean new reviews/wk | Est. units (4% rate) | Est. units (3% rate) | Est. units (2% rate) |
|---|---|---|---|---|---|---|
| 01-12 (above the fold) | 581 | 2 | 1.83 | 46 | 61 | 91 |
| 13-24 (page 1 mid) | 524 | 0 | 0.58 | 15 | 19 | 29 |
| 25-48 (page 1 tail) | 1069 | 1 | 0.81 | 20 | 27 | 40 |
| 49-72 (page 2) | 1053 | 0 | 0.42 | 11 | 14 | 21 |
| 73+ (page 3+) | 677 | 0 | 0.17 | 4 | 6 | 9 |
What the daily feed looks like
Organic rank trajectories for the top listings in Shoe Racks & Cubbies across 28 days. Rank 1 sits at the top of the axis. This is the shape of the ongoing feed — the final day is the real snapshot, the preceding days are illustrative.
Daily organic rank, Shoe Racks & Cubbies
One line per SKU · lower is better
How to make this exact
The unit estimate divides weekly review deltas by an assumed review rate. An assumption is fine for ranking competitors against each other, but you can do better — and this is the single highest-value step available to SONGMICS HOME.
You hold Partner Home unit sales for your own SKUs. Give us one quarter of those against the same weeks of review deltas and we solve for your actual review rate, per category. That converts the proxy into a calibrated unit model — which we then apply to every competitor listing on the shelf, where you have no visibility today. Your own ground truth becomes the instrument that reads the rest of the market.