Offer — The core unit of configuration: products, discount, Smart Rules, behavior mode, and display/translation settings. Called a "Rule" in the API and codebase; "Offer" everywhere in the product UI and these docs.
Context — A single placement an offer can target, e.g. cart-drawer or post-purchase. There are 13. An offer's context field is an array, so one offer can span several.
Funnel step — A grouping of related contexts: product page, cart, checkout, post-purchase, thank-you, POS. Six total; used for navigation and for which contexts can be multi-selected together on one offer.
Surface — Used in these docs interchangeably with "context" when describing capabilities informally; the CMS/code term is context.
Behavior mode — What happens to the cart or order when an offer is accepted: standard, auto-add, swap, mix & match, or popup.
Smart Rule — A targeting condition that must pass for an offer to show. 25 total, across five categories (Cart Contents, Cart Value & Quantity, Audience, Trigger, Context). All active rules on an offer must pass; there's no OR logic between rules on one offer.
Trigger rule — A Smart Rule category unique to the product-page context, targeting the specific product or collection currently being viewed.
Impression — One instance of an offer being shown to a shopper, regardless of whether they acted on it.
Conversion — One instance of an offer being accepted.
Attach rate — Orders containing at least one upsell divided by total orders. A store-wide figure, not a per-offer conversion rate.
Upsell revenue — Revenue generated by UpsellPlus offers, net of discounts. The figure plan tiers are measured against.
ShopBrain — UpsellPlus's automated recommendation engine; selects an offer's products dynamically rather than from a fixed list you choose.
Earn — A separate program where UpsellPlus places third-party partner offers on your thank-you/order-status pages and shares resulting revenue with you, rather than you configuring an offer of your own.
Experiment — An A/B or multivariate test of variants of one base offer, with its own traffic allocation and sample-size calculation, layered on top of (not replacing) that offer's own Smart Rules.