Turn this on for daily or recurring monitoring. The first run returns every matching product as NEW. Later runs normally return only NEW, UPDATED and REAPPEARED products, which makes it a cheap way to watch price drops. What is compared: price range, was-price, discount, on-sale flag, price type, name, brand, description, fit and fabric text, every colour with its own price and the size table. What is excluded by default (still returned in the row, never a change): scrape timestamps, the product's rank and page, where it was found (link, keyword, category), ratings and reviews (average rating, review count, rating breakdown, fit summary and the review sample), the rotating promo and 'new' flags, and image links. Stock and availability (in-stock flag, units, per-colour and per-size stock) are also excluded unless you turn on 'Count stock changes', because they move with every order. Colour and size lists are compared regardless of the order the store returns them. 'Changes to watch' narrows this to price (and stock when counted) only. Turn on 'Emit unchanged' or 'Emit expired' only when you also want those rows returned (and billed). State is kept separately for each scope and filter setup; use State key to name or deliberately share a monitoring campaign. To continue one specific interrupted run instead, use Resume from a previous run above.