Harpy Glossary

WoW (Week over Week)

Amazon & D2C glossary · Harpy Media

WoW (Week over Week) compares this week’s figure with last week’s: the highest-frequency trend view that is still worth having. It is used across sales, units, traffic, conversion, availability, and advertising performance.

What is WoW?

Its strength and weakness come from the same property. A weekly comparison responds quickly enough to catch a problem while it is small — a campaign that stopped working, a listing that lost its buy button, availability that started slipping. It is also, used alone, the most misleading comparison in routine reporting, because a single week contains plenty of variation that means nothing.

What it is genuinely good for

Three uses. Detecting immediate effects: a promotion, a price change, or a content edit shows its first honest signal within a week. Operational monitoring: availability, dispatch performance, and stock cover can deteriorate quickly, and weekly reading catches the direction before it becomes a shortage. And catching anomalies, since a sudden move in any metric usually has a specific cause that is findable while it is fresh.

The common thread is spotting, not concluding. Weekly comparisons tell you where to look; they do not tell you what is true.

Reading it without over-reacting

Three disciplines. Compare against a longer window as well — the trailing month gives the weekly figure a context, and a movement that appears in both is a real change rather than noise. Look for persistence, since two consecutive weeks in the same direction is a pattern and one is a data point. And check the obvious explanations before concluding anything: a promotion ended, a holiday fell in the week, a competitor launched, or a product went out of stock.

The failure mode is a business that changes course every week in response to the newest number, never allowing any intervention to run long enough to be measured. Movement is not the same as progress, and a brand constantly reacting has no way to tell which of its changes worked.

WoW Growth (%) = ((This Week − Last Week) ÷ Last Week) × 100Spotting tool, not a conclusion. Always pair with a longer window before acting.

In practice

A brand reviews weekly figures on Monday, flags anything that moves outside its normal range, and investigates rather than acting immediately. A persistent decline over two weeks is traced to a competitor’s pricing move; the response is decided once, on evidence, rather than adjusted repeatedly against noise.

⚠️ Watch out. Managing the business weekly. A brand changes bids, prices, and content every week in response to the latest comparison, so no intervention runs long enough to be assessed. The dashboard is active and the business is not improving, because nothing is ever given time to work.

💡 Harpy tip. Use week over week to spot and the longer windows to conclude. Look for two consecutive weeks before treating a movement as a trend, and check the mundane explanations first — most weekly movements are promotions ending or holidays falling.

How Harpy Media helps

Weekly rhythm is part of how we run accounts: fast enough to catch problems early, disciplined enough not to act on noise, and always read alongside the longer windows before anything changes.

WoW FAQ

What is Week over Week?

A comparison of this week’s figure against last week’s — the highest-frequency trend view worth tracking, applicable to sales, traffic, conversion, availability, and advertising.

What is it best for?

Spotting: immediate effects of a change, operational deterioration, and anomalies. It tells you where to look rather than what is true.

Why is it risky alone?

Because a single week contains normal variation that looks like a trend. Pair it with a longer window, look for persistence across two weeks, and check the obvious explanations first.

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