South Africa, June 30 -- A few years ago, almost none of this existed. Today, businesses from Woolworths to ARC to Bash are turning their first-party data into media, and they are not alone.

We have largely stopped calling it retail media because retail was only the opening act.

And yet advertiser budgets are not shifting at the pace that growth suggests. The reason is not a lack of appetite. It is that the market has built the supply far faster than it has built an easy way to buy it.

Unglamorous

This is the part nobody likes to talk about, because it is unglamorous.

For an advertiser, tapping all that supply still means assembling it.

A separate conversation and plan with every partner. The same manual stitching, by hand, every ti...