In the MerRec case study, we rank 5,000 brands by betweenness centrality in a graph of shared fans to find the brands that connect different shopping communities. But when you run this on real marketplace data, you run into an immediate catalog problem: twelve of the top twenty entries aren't independent brands at all. They are retailers (Walmart, JCPenney, Macy's), store brands (Mainstays), or catch-all bucket labels that sellers select from the brand dropdown (As Seen on TV, Customized & Personalized, Eyeshadow).

Because shoppers across every category buy from Walmart, Walmart creates artificial shortcuts between worlds that no actual manufacturer provides. If you want an honest picture of brand affinity, you have to get those catalog artifacts out of the graph. This post walks through how we pull them out, why naive filtering fails, and how the ranking shifts once the graph is rebuilt.

Which brands moved toward Barbie's audience around the July 2023 film release? An agent put that question to Algeon over Arrow Flight SQL, using MerRec, a dataset of 1.27 billion marketplace events. The query compared brand affinity in May-June with July-August. Primark and AMC appeared near the top, alongside the cosmetics brand NYX in first place and Taylor Swift in fifth. What could explain those changes?