Markets and Periods: MULO, xAOC and the Provider Calendar

A market is a defined set of stores rolled into one reportable number. Every syndicated figure you read belongs to one. Each provider defines its own markets and runs its own calendar, so "last month" does not cover the same weeks across providers. When assessing any syndicated number, ask two questions: which stores, and which weeks?

What a market actually is

A market in syndicated data is a defined store set rather than a place on a map. It can be a channel, a geography, a single retail account, or a roll-up combining several. The provider projects its store universe into each definition, and every measure in Chapter 4 is computed within one. Your % ACV is never simply 38%; it is 38% of a specific market's ACV, and changing the market definition changes the number.

The big roll-ups

MULO is Circana's multi-outlet view, combining grocery, drug, mass, club, dollar and military channels [2]. Two variants are routinely confused and they are different kinds of thing. MULO+ is an expanded universe, launched in January 2024, which added 11 retailers and major e-commerce and increased coverage by more than 15% [3]. MULO+C is the variant that adds convenience stores [2].

xAOC (extended all outlet combined) is Nielsen's equivalent broad market and can also include convenience in its channel total. SPINS publishes Circana channels as well as its own Natural Expanded channel view.

These roll-ups are what people mean when they say "total US" in a conventional-channel conversation. They are built from similar channel lists but from different store universes, under different projection rules, on different calendars, so a brand's MULO dollars and xAOC dollars track each other directionally and never match exactly.

The natural channel is its own arena

SPINS defines its markets around channel realities the conventional roll-ups blur. Its Natural Expanded Channel covers natural and wellness-focused retailers, more than 2,500 stores doing over $40 billion in sales [1].

SPINS applies its own qualification criteria to decide which retailers belong in the Natural Expanded Channel rather than treating the label loosely [4]. Check with your provider, as these definitions are subject to change.

The natural channel and conventional channel are typically viewed as different competitive arenas with different assortments, different shopper missions, different price expectations. This is why a brand strong in one can look ordinary in the other on identical numbers.

The calendar

Providers run their own calendars, and three facts follow.

First, provider weeks close on the provider's schedule, not on the month's last day. A syndicated reporting period is a block of weeks, and providers publish a range of rollups: 4, 12, 24 and 52 weeks are common, as are 13 and 26.

Second, the same-named window ends on a different day depending on the provider. Nielsen weeks run Sunday to Saturday. Circana weeks run Monday to Sunday [5]. So a Circana "latest 4 weeks" and a Nielsen "latest 4 weeks" contain different selling days by construction. Put two providers' trends on one slide without aligning week endings and part of the gap between the lines is just the calendar.

Third, periods interact with restatements from chapter 2: the historical periods in this month's file may have been recomputed since last month's file. Date every extract.

Comparing across markets without fooling yourself

Compare rates, not totals, whenever the store sets differ. Any measure with ACV in its name is already a rate, which is exactly why it neither sums nor averages casually, the subject of the aggregation trap.

And remember the hierarchy. Two providers can measure the same stores in the same weeks and still disagree on your share, because they drew the category boundary differently and are therefore dividing by different denominators.

Where the definitions live in practice

None of these definitions travel inside the data file. The extract says "MULO" or "Natural Expanded" in a column header and assumes the reader knows the store set, the calendar, and the rules behind it. In Sous, that knowledge is written into each provider's rulebook: market definitions and period calendars are encoded so a question like "how did we do in total US last month?" resolves to the right roll-up and the right 4 weeks for that specific provider. The architecture behind that is covered in how an agent works with syndicated data.

Common questions

What is a syndicated period? A provider-defined block of weeks, published in a range of rollups: 4, 12, 24 and 52 are common, as are 13 and 26. Periods follow the provider's calendar rather than calendar months.

What is the difference between MULO and xAOC? Both are broad multi-channel roll-ups: MULO is Circana's, xAOC is Nielsen's. They combine similar channel lists but different store universes, projections and calendars, so the totals differ. MULO+C is the Circana variant that adds convenience; MULO+ is a separate, expanded universe.

Why don't my Circana and Nielsen numbers match? Different store universes, different market definitions, different product hierarchies and different week endings. Expect direction to agree and levels to differ.

Which market should I use with a retailer buyer? The one that reflects the competitive universe the retailer is in, and the products that you benchmark yourself against. In practice that usually means their account market where you have it, and otherwise the roll-up their category team plans against.