What do customers remember about an online order?

Whether it arrived when you said it would, and what happened when something went wrong. Almost nothing about the website survives in memory a week later.

The reasoning

That is why the delivery estimate matters more than the product page. A store that promises four days and takes four is remembered as reliable; one that promises two and takes four is remembered as late, on the same delivery.

What most people get wrong

Delivery is what a customer remembers, and it is the part most stores control least.

A refund handled well makes a repeat customer more often than a sale handled well.

Most support questions are the same five, and answering them before they are asked is cheaper than answering them after.

How an app changes it

An app makes the after-sale part easier: order status, reordering and support in the place the customer already has open.