Turn this on for daily or recurring monitoring. The first run returns all matching offers as NEW. Later runs normally return only NEW, UPDATED, and REAPPEARED offers. Turn on "Emit unchanged" or "Emit expired" only when you also want those offers returned (and billed). State is kept separately for each search/URL and filter setup; use State key when you want to name or deliberately share a monitoring campaign. To continue one specific interrupted run instead, use Resume from a previous run above. Rating value/count, the recent-buyers label and count, and review text do not by themselves count as a change (other shoppers buying, rating or reviewing the product is not something you asked to monitor); price, stock status (isInStock), discount flag, delivery cost, shipping text, seller details, thumbnail and the other offer fields do trigger UPDATED. Offers saved by an older version of this actor are not flagged UPDATED just because these newer fields appeared; the newer fields are tracked from the following run.