Why this matters
Decomposing TDP is the discipline of splitting any TDP change into its two arithmetic drivers — ACV change and SKUs-per-door change — so the brand can tell apart genuine door expansion, assortment growth, and store-mix shifts. The same headline number can mean three completely different commercial stories.
A category manager opens the quarterly distribution recap. TDP at Sprouts is up +18%. Headline goes in the deck, sales team takes it to the buyer review, the brand celebrates.
The GM asks one question: "What's actually driving the +18%?"
There are three different commercial answers behind the same +18% TDP number — and each implies a completely different next move. A TDP gain from genuine door expansion is a sales-team win. A TDP gain from adding a slow-moving SKU at existing doors is a working-capital problem disguised as growth. A TDP gain from losing small doors and keeping the large ones is a quality-of-distribution shift that needs its own conversation.
If you can't decompose TDP, you can't tell which one you're looking at. This page is the decomposition.
The decomposition math
The definition (covered in detail in What is TDP):
TDP = ACV % × average SKUs per carrying store
Two inputs, one output. So a TDP change has two arithmetic drivers:
% ΔTDP ≈ % ΔACV + % Δ(SKUs/carrying store)
(The approximation is exact for small changes and within a percentage point for changes under ~20%.)
Whichever input moved more is doing more of the work. The decomposition table for any TDP change:
| ACV change | SKUs/door change | What this means |
|---|---|---|
| Up | Flat | New doors. Distribution is genuinely expanding. |
| Flat | Up | Assortment growth. Existing buyers see more of the brand at the shelf. |
| Up | Up | Both moving. Disambiguate using store-count change to see whether new doors are also carrying more SKUs. |
| Up | Down | New doors are carrying fewer SKUs each. Often happens when conventional grocery picks up a single hero SKU. |
| Flat | Down | SKU pruning at existing doors. Could be intentional (rationalization) or a warning sign (delistings). |
| Down | Up | Door loss but the surviving doors stocked more SKUs. Often a quality-of-distribution story. |
| Down | Flat | Door loss. Genuine distribution contraction. |
| Down | Down | Both contracting. Worst case — usually a real problem. |
You only need three numbers to fill in this table: ACV change, average SKUs per carrying store change, and (as a sanity check) raw store count change. SPINS exposes all three at the brand × retailer × channel level.
Worked example — same +15% TDP, three different stories
Three brands at Sprouts, each reporting a +15% TDP change quarter over quarter. Same headline number; the inputs are completely different.
| Brand | Q4 ACV → Q1 ACV | Q4 SKUs/door → Q1 SKUs/door | Q4 TDP → Q1 TDP | Story |
|---|---|---|---|---|
| A — emerging wellness | 50% → 57.5% (+15%) | 3.0 → 3.0 (flat) | 150 → 172 (+15%) | Pure door expansion |
| B — established snack | 80% → 80% (flat) | 4.0 → 4.6 (+15%) | 320 → 368 (+15%) | Pure assortment growth |
| C — natural beverage | 60% → 66% (+10%) | 2.5 → 2.6 (+4%) | 150 → 172 (+15%) | Mixed — both contributing |
Same TDP gain, very different commercial implications:
- Brand A is winning new doors. The sales team's pitch is working. The investment question is whether the new doors will add more SKUs over time (TDP compounding) or stay single-SKU. Velocity in new doors should be the next metric checked — a brand that adds doors with weak velocity gives back the gain in delistings within two cycles.
- Brand B has saturated its door footprint at Sprouts (80% ACV is near the practical ceiling). The +15% TDP came from getting an additional SKU onto existing shelves. The question is whether the new SKU is incremental to the line or cannibalizing existing SKUs. Velocity per SKU should be checked — average velocity per SKU often drops 5–10% when assortment expands without category expansion.
- Brand C has both factors moving, but the ACV gain (+10%) is dominant. Most of the +15% TDP is door expansion with a small assortment lift on top. Probably driven by a buyer adding the brand to additional regions and stocking a slightly broader pack.
A category review that walks in with "TDP up 15%" leaves money on the table compared to walking in with the right one of the three sentences above.
Why ACV-only views miss this
ACV alone is the right "are we getting onto shelves" metric — but it's blind to depth. Brand B's +15% TDP doesn't register in an ACV-only report. The sales team chasing pure ACV growth would correctly mark Brand B as "flat" and miss that the shelf footprint expanded. The TDP decomposition is the only view that catches both expansion modes.
For the cross-cutting question of which metric answers which type of question, see Velocity vs. share of shelf vs. TDP — which metric to use when.
Worked example — decomposing a TDP decline
Decompositions of TDP gains are the easy case. TDP declines are where the decomposition actually changes the commercial response — because "we lost distribution" and "we got pruned" require different fixes.
A natural beverage brand reports TDP at Natural Grocers down −12% quarter-over-quarter. Three possible underlying patterns:
| Brand scenario | Q4 ACV → Q1 ACV | Q4 SKUs/door → Q1 SKUs/door | Q4 TDP → Q1 TDP | Story |
|---|---|---|---|---|
| D — lost doors | 70% → 61.6% (−12%) | 2.5 → 2.5 (flat) | 175 → 154 (−12%) | Distribution contraction at the door level |
| E — pruned at existing doors | 70% → 70% (flat) | 2.5 → 2.2 (−12%) | 175 → 154 (−12%) | Buyer rationalization at existing stores |
| F — small-store loss with assortment gain | 70% → 67% (−4%) | 2.5 → 2.3 (−8%) | 175 → 154 (−12%) | Mixed: lost smaller doors and reduced SKU count at survivors |
Same TDP decline, very different action items:
- Brand D has a door-loss problem. Likely a regional buyer who exited the brand, or a chain-level reset. The recovery path is a buyer-relationship conversation aimed at re-stocking the lost doors.
- Brand E has an assortment problem. The buyer kept the brand but dropped a SKU per store. Likely either a slow-moving SKU was rationalized or a competitor took the slot. The recovery path is defending the remaining SKUs and earning back the dropped slot with velocity data.
- Brand F has both — usually the harder situation because it signals broader competitive pressure. The recovery path starts with diagnosing whether the small-door loss was buyer-initiated (cost-cutting at small stores) or shopper-initiated (low velocity driving the buyer's decision).
The TDP-only report shows −12% for all three. The decomposition is the only view that surfaces which conversation to have.
Decomposing TDP at the SKU vs. brand level
The same decomposition math applies at two natural rollup levels, and they tell different stories:
- Brand-level TDP asks: across all of our SKUs, how broad and deep is our distribution? This is the executive-summary view.
- SKU-level TDP asks: for a specific SKU, what's its ACV and what's the store-count footprint? This is the buyer-conversation view.
A brand-level TDP gain can come from one SKU's strong door expansion, from the slow accumulation of small SKU-level wins across the line, or from the launch of a new SKU. The brand-level number doesn't tell you which. For diagnosing where growth is coming from — or where erosion is starting — the SKU-level TDP cut is what surfaces the pattern early.
A practical example: a brand reports brand-level TDP up 8%. At the SKU level, four of five existing SKUs are flat or down, and the newly launched fifth SKU is contributing 10 points of the brand-level TDP. Reading only the brand-level number, the team would call this "the brand is winning." Reading the SKU-level decomposition surfaces that the existing line is stagnant or contracting and one new SKU is masking the broader trend. That's a very different strategic picture than "the brand is winning."
The corresponding anti-pattern: reporting brand-level TDP gains without an SKU-level decomposition during a recent product launch. Launches almost always inflate brand-level TDP for a few quarters as the new SKU ramps; that inflation is real but doesn't tell you what the rest of the line is doing.
Reading TDP decomposition across retailers
A multi-retailer brand will often have very different TDP decompositions at different retailers — and the variation is itself strategic information. A wellness brand might see, in the same quarter:
| Retailer | ACV change | SKUs/door change | TDP change | Reading |
|---|---|---|---|---|
| Sprouts | +6% | +3% | +9% | Both factors working — strong relationship |
| Natural Grocers | +12% | flat | +12% | Door expansion underway, assortment still narrow |
| Independent natural (KeHE/UNFI) | +2% | +8% | +10% | Assortment depth growing at existing doors; door growth slow |
| Target Pet | flat | flat | flat | Steady-state — neither factor moving |
Four different commercial stories under one brand-level TDP roll-up. The strategic implication: the right next move at Sprouts is different from the right next move at Natural Grocers, which is different from the right move with KeHE/UNFI buyers. A consolidated TDP-up report at the brand level would smooth all four into one number and miss the per-retailer texture.
Anti-patterns
- Reporting TDP change alone. A standalone TDP number is unparseable. Always show the ACV and SKUs/door alongside it. The three-column view is the minimum defensible report.
- Treating SKUs/door change as "more shelf space". A new SKU at an existing door is sometimes a true facing gain and sometimes a swap (the buyer removed an under-performing SKU and replaced it with yours). Cross-check share of shelf where you have it — see What is share of shelf? — to distinguish facing gains from one-for-one swaps.
- Ignoring store-count change when ACV moves. ACV can shift from panel composition rather than door count — the brand "gains ACV" because the panel reweighted, not because a new store added the brand. The diagnostic: did raw store count move in the same direction as ACV? If not, you're seeing weighting drift. See Reading SPINS panel coverage.
- Comparing TDP across categories without normalization. A 200 TDP in cereal isn't comparable to a 200 TDP in shelf-stable beverages — the category-typical SKU counts per store differ. Cross- category TDP comparison is noise unless category-normalized.
- Mistaking SKU bloat for growth. Adding a low-velocity SKU to existing doors raises TDP and lowers velocity per SKU. The TDP report cheers; the buyer notices the velocity drop at the next review. Always pair TDP-up-from-assortment with velocity-per-SKU trend.
Doing this in Scout
Scout's brand-performance views surface ACV, average SKUs per carrying store, raw store count, and TDP as adjacent columns from the SPINS extracts you already pull. The decomposition table above is the default cut — "TDP up 15%" sits next to "ACV up 10%, SKUs/door up 4%" without a pivot. For retailer × time-period drilldowns, the same three columns travel together, so the diagnostic question ("door expansion or assortment growth?") is a glance rather than a spreadsheet derivation.
Summary + further reading
- TDP is a product of ACV and SKUs per carrying store. A TDP change has two arithmetic drivers; either or both can move.
- The same TDP headline can come from door expansion, assortment growth, or quality-of-distribution shift — each implying different commercial actions.
- Always report TDP with ACV and SKUs/door alongside, and cross- check raw store count to catch panel-weighting drift.
Related: What is TDP? · What is ACV? · Velocity vs. share of shelf vs. TDP — which to use when