Flags two patterns: an offer with zero conversions despite real click volume, or an offer whose conversion rate has dropped sharply vs. its own recent history. Either can be completely normal (a genuinely low-converting offer, seasonal dip), but both are also exactly what you'd see if a brand quietly stopped firing their postback (see the Postback page for that URL) or started under-reporting. Click any flagged offer to see the per-publisher breakdown - if every publisher on that offer shows the same drop, it points at the brand; if it's just one, it points at that publisher instead.