Checkout is not the end of the relationship
Checkout is treated as the end of the customer journey because it is the end of the purchase path. Ownership begins there, and with it a different set of questions: how to care for the product, how to use it, whether it still belongs in the customer’s life, and whether the brand still has something useful to offer.
Connected products continue the journey
Connected products and post-purchase experiences are not a separate channel so much as a continuation. When that continuation is missing, the relationship has to be rebuilt from advertising the next time around.
Notice the useful moments after purchase
The useful work is to notice which moments after purchase could carry meaning, and which tools — content, service, identity, or a connected layer — would actually help.