Narrow, balanced and broad tiers survive at 2.5%, 5% and 10% for video buyers. Seed lists start above 100 matched people, and two Google pages now disagree.

Search engine marketing is the purchase of placement on search results pages through keyword auctions, priced per click and resolved by Ad Rank at query time.

Content marketing distributes content useful enough to be sought out rather than sales material. How the discipline works, and what AI search has done to it.

Social media marketing is brand activity on social platforms, paid and unpaid. How the auction works, where the creator layer sits, and why measurement fails.

AI marketing is marketing where a model, not a person, makes the decision. How the prediction, generation and agent layers work, and where each one still fails.

Rank trackers needed 500 to 1,000 requests to resolve a single five-page ranking. Google has not documented the goto parameter or said whether it is permanent.

Nine item categories now carry fixed cushion, crate and label duties, split at a 10 kg line. One unresolved drafting note survived into the published table.

Seventeen funnel predictions replaced one hand-tuned formula, giving search teams a personalised weighting. Whether 0.36% survives beyond one platform is open.

GMV, gross merchandise value, is the total value of goods sold through a platform before fees and returns. How it is calculated, used in ads, and disputed.

Reinforcement learning is machine learning by trial and error against a reward signal. How it sets advertising bids, trains chatbots, and where rewards fail.

Click-through rate is clicks divided by impressions, the oldest metric in digital advertising. How clicks are counted, what breaks the ratio, and why it fell.

3PL means third-party logistics: an outside firm that stores, picks, packs and ships another company's goods, and sets the delivery promise that ads rely on.

SKU, or stock keeping unit, is the internal code a company assigns to each distinct sellable item, and it has now become the unit of retail media measurement.

Dropshipping is retail where the seller holds no stock and a supplier ships direct to the buyer. How the order flow, margins, platform rules and ad spend work.

Sixteen terms, four groups of four, drawn from wider than the ad stack reaches. One group reads like plain commercial English and is doing something else.

YouTube's views co-viewed metric estimates household TV viewers but appears only in creator analytics, a sponsorship figure that brands have no way to audit.

Spread is the gap between what a buyer pays for advertising and what the seller receives, kept by an intermediary trading on its own account, not as agent.

Arbitrage is buying advertising traffic or inventory at one price and reselling it higher, a practice spanning search, programmatic supply and agency deals.

Promotion: a time-bound offer of extra value attached to a listing or ad as structured data, kept separate from price. How the feeds, assets and policy work.

Place is the marketing mix element covering where a product can be bought. How distribution decisions govern feeds, marketplaces, retail media and AI agents.

Product is the structured record describing one sellable item that advertising platforms ingest, validate and match to queries across paid and unpaid surfaces.