Every pool in a strategy has a distribution type. It answers one question: which catalogs does this pool go into? There are three answers, and they combine. This article describes what each one does in the engine and what it is for.
Guaranteed: every catalog
A Guaranteed pool appears in every catalog the strategy produces. You set how many products from the pool go into each catalog. If the pool holds more products than that, each customer gets a different draw from it; if it holds exactly that many, everyone sees the same ones.
Use it for the products you want in front of everyone: the staples, the new arrival, the thing the campaign is about. A strategy with only Guaranteed pools makes identical catalogs, which is sometimes exactly right, for a launch for instance, but it gives up the uniqueness that makes a catalog feel personal.
Chance: some catalogs
A Chance pool goes into a share of catalogs. At 25%, roughly one customer in four gets a product from it. The percentages across all Chance pools in a strategy add up to 100%, so they describe how the Chance slots are divided, not an independent coin flip per pool.
Chance pools fill the catalog after Guaranteed and Limited pools have taken their slots, up to the strategy's maximum of 2 to 12 products. This is where variety comes from: three Chance pools at 50%, 30% and 20% give every customer a different mix of your main collection, your accessories and your seasonal line, and no two pages look alike.
The Distribution setting changes how the engine picks within a Chance pool. Even draws by chance alone. Balanced weighs in inventory. Inventory strongly prefers products with more stock. The percentages stay the same; the choice of which product fills the slot changes.
Limited: until it runs out
A Limited pool appears in catalogs until the number of customers you set has received it, then stops. Later catalogs in the same run do not get it. It behaves like limited stock, which is what it is for: the deepest discount, the hero product, the thing that should feel scarce because it is.
How the allocation is handed out depends on the campaign type. An Outreach run knows its whole audience up front, so the engine assigns the Limited pool to random recipients when the catalogs are minted. A Storefront run does not know who will visit, so it paces the allocation across visits for the length of the run.
Two things to know. A strategy needs at least one Guaranteed or Chance pool; a strategy that is only Limited can produce empty catalogs once the pool is spent. And a Limited pool sets counts, not odds: if you want a fixed number of deep deals, this is the tool, not a range with a rare top end.
How the three fit together
Think of the catalog as slots. Guaranteed and Limited pools claim theirs first. Chance pools fill the rest. A typical shape:
| Pool | Type | Why |
|---|---|---|
| Two best sellers | Guaranteed, 1 per catalog | Everyone sees a product they recognise |
| Main collection | Chance, the biggest share | Variety from page to page |
| Accessories | Chance, a smaller share | Fills the page without discounting the core line deeply |
| One hero product | Limited, capped | The deal worth talking about, to a set number of people |
Each pool carries its own discount, fixed or a range, so the hero can be deep while the staples stay shallow. See Designing a discount strategy for the margin side and How deep should your discounts be? for the ranges.
When a product disappears mid-run
A product can sell out, be unpublished, or drop below your stock minimum while catalogs are live. The strategy's rule decides what happens to its slot: remove it from the catalog, or replace it with another product drawn from the strategy's Chance pools. Live catalogs update within about a minute. The defaults come from Settings → Inventory and can be changed per strategy.
