RankRobin: Sort Collections

Auto-sort any Shopify collection by what's selling - units sold, revenue, trending, or year-over-year. Push out-of-stock products to the bottom automatically. Build "Black Friday bestsellers" or "Last Christmas top 20" collections that auto-populate from past sales. Stack multiple years for richer signal. Reuse one template across dozens of collections. Pin priority products above the algorithm. RankRobin writes to native Shopify sort order - no theme edits.