The price changed. What actually changed?

Start with a decision you can name

A competitor’s lower price can trigger a reaction before anyone checks the offer. Is it the same variant, the same pack size, and the same market? A useful monitoring process answers those questions before it tells a team that a price has moved.

Choose a narrow decision for your first watchlist: investigate a change on a matched product, review a promotion, or update a buyer’s comparison. This guide describes our suggested workflow. It does not report collected prices, retailer performance, or a live market benchmark.

Define the offer, not just the page

Keep an offer record for a particular seller, product variant, pack size, destination market, and observation time. Record the currency explicitly. A product URL alone may lead to a default variant, a location-specific offer, or a price that depends on a membership.

Google Merchant Center treats price, currency, and availability as distinct parts of product information. That is a useful reminder for research as well: a number without its offer context is difficult to compare. Check platform-specific requirements in the source documentation rather than assuming the same rules apply to every marketplace.

Keep a raw record and a comparison record

Preserve the displayed amount separately from any calculated comparable price. If you normalize a two-pack into a per-unit price, record the original quantity and the calculation. Do not silently replace the original observation with a derived number.

Use a consistent shipping destination and a clearly stated tax basis for a comparison. If those conditions cannot be established, mark the record as incomplete. A missing shipping amount should not automatically become zero shipping.

• Separate list price, sale price, and coupon-dependent offers.
• Record whether the offer needs membership or a minimum basket.
• Keep unavailable and unknown availability as different states.
• Retain enough evidence for a second person to review the change.

Review a change before acting on it

An alert should identify the previous comparable observation, the new one, and the reason it crossed your review rule. A changed pack size or selected variant may explain a large price difference without any underlying repricing.

Give uncertain records a human review path. Before adjusting your own offer, check the variable costs and contribution that remain at the proposed price. Our price scenario calculator explores those entered assumptions; it does not predict demand or tell you what a retailer will do next.

Choose a useful cadence

Monitor at a frequency that fits the decision and the permitted source access. More observations are not automatically more useful. A small, consistently reviewed watchlist can be easier to maintain than a broad collection with unclear matches.

Keep the collection method, source permissions, market, and coverage limits with the report. Do not describe an incomplete watchlist as the whole market. The strongest output is a reviewable change and a clear next step.