Retail has more customer data than almost any other sector and the hardest time making one coherent thing out of it. The same shopper browses on mobile, buys in store with a loyalty card, returns online and complains on WhatsApp, and in most estates those are four unrelated records. Everything downstream, from personalisation to paid media efficiency, is limited by how well that gets resolved.
Retail also carries the heaviest operational data load in martech: product feeds, stock, price changes, promotions and order status all have to stay in step across the website, the app, email, the ad platforms and the marketplaces. When those drift, you advertise products you cannot ship and personalise around prices that no longer exist.
It is also the sector where the stack gets judged in public. A tracking gap that costs a little in March costs a great deal in the ten days before Christmas, and a feed that drifts on Black Friday morning advertises stock you do not have to the largest audience of the year. We design for peak, not for the average Tuesday.