I keep a plain three-column note for prices, shipping ranges, and restock dates when I’m comparing two storefronts. Over eight weeks I logged 11 check-ins: shipping quotes moved by two days, one price matched to the cent, and the restock gaps lined up almost the same.
It felt less like coincidence and more like I was looking at one operation wearing two signs. For those of you who track this stuff, what little numbers or patterns make you suspect two shops are actually the same outfit?