Ecommerce analytics track cross-channel customer LTV by linking every purchase a single customer makes, regardless of which platform or channel they used, into one unified profile instead of separate, disconnected records. Customer lifetime value only tells the truth when it accounts for every touchpoint: Shopify Online, Amazon, TikTok Shop, retail, and wholesale, all attributed to the same person.

Most stores calculate LTV using Shopify data alone, which means a customer who also buys through Amazon or a marketplace app looks like three different, lower-value customers instead of one high-value one. This guide walks through how to actually unify that data, what breaks the calculation, and how to build an LTV model you can trust enough to guide retention spend.