Explain How Amazon Price-History Trackers Gather Prices and Send Drop Alerts

Explain how third-party price trackers for Amazon work: the websites and browser extensions that show how an item's price has changed over time and alert shoppers when it drops. ```hint Follow one price Trace a single price from the moment it appears on an Amazon product page to the moment a shopper receives an alert. Each part of the tool sits somewhere on that path, and each step has a limit worth naming. ``` ### Clarifying Questions - Should I explain only the technical mechanics, or also how such a tool attracts shoppers and earns money? - Is the tracker an independent company with no special access to Amazon's systems, or can I assume a data partnership? - Which surfaces are in scope: a website where shoppers paste a product link, a browser extension that works on the Amazon page itself, or both? ### What a Strong Answer Covers - The jobs the tool does for shoppers, such as price history, drop alerts and in-page overlays - Where price data can come from and the limits of each source - How products are identified and how checks are scheduled, stored and turned into alerts - How the tool makes money and how that shapes its features - Data-quality, freshness, cost, privacy and policy risks ### Follow-up Questions - You track millions of products but can afford to re-check only a fraction each hour. How do you decide which ones to check? - How would you spot a fake discount, where the price is raised shortly before a "sale"? - If Amazon cut off your main data source, what would you change?