In theory, this makes a lot of sense and seems to be the obvious way to personalize the customer experience along the life cycle of an individual customer. However, in practice the insights and conclusions derived from this activity is hard to project on the actual customer or group of customers in advertising campaigns. Often a campaign is targeted using other characteristics than those above, such as demographical or interest based audiences. These are of course good and useful, but the idea to convey certain messages depending on where on the customer journey a customer is will not be adressed by such targeting. An improvement is the retargeting of visitors that is widely used, and in best case the use of dynamic ads based on what product was viewed or added to cart. But these audiences are often not suppressed as the customer moves along in the customer journey or funnel. I guess we've all been stalked by ads for items we already purchased.