Is the old marketing agency business model officially dead or hotter than ever?

WPP started out making shopping baskets in Kent. Martin Sorrell bought into the shell in 1985 and spent 30 years building it into the biggest advertising group in the world. Then came the slide: in December it was kicked out of the FTSE 100 after 27 years, its market value had sunk from about £24bn in 2017 to around £3.2bn, and its headcount fell by more than 9,000 over the year to 98,655.

The easy story says artificial intelligence is eating adland. That’s too neat. What AI has really broken is the way agencies bill. For decades, the business ran on time: retainers, rate cards, teams stacked like pyramids. But if a job that used to take 20 hours now takes five, the old model quietly turns efficiency into a price cut. Roughly three in ten agencies say clients are already demanding discounts because the work is faster.

And the pressure is coming from inside clients as well. In 2008, 42% of members of America’s Association of National Advertisers had an in-house agency. By 2023 that had climbed to 82%. Those teams are no longer just cheap production shops. In the association’s latest survey, only 9% said saving money was the main reason for having one, while 53% said the internal team was there to deliver strategic creative work. That’s a direct competitor sitting at the table, not a back-office helper.

So the industry is drifting toward outcome pricing. McKinsey says about a quarter of its global fees are now tied to results, not scope and duration. WPP says between a fifth and a quarter of its net sales are already performance-linked, and it has committed to decoupling revenue from headcount. That is a big shift for an industry that used to treat the billable hour like holy writ.

The problem is that outcome pricing is brutal. If the result can’t be controlled, the fee can’t be safely claimed. Every handoff between strategy, execution and different agencies becomes a place where blame can disappear. That’s why mid-sized firms like Mediacharge are selling consulting and execution together, with clients including Nemetschek’s Bluebeam, DACHSER, LexisNexis and, in 2026, Honda. They’re not pitching cheap. They’re pitching accountability, which is usually the more expensive thing.

There are still real objections. Attribution is getting fuzzier, not cleaner. Privacy rules, walled gardens and AI answers that never produce a click all make measurement messier. And paying for outcomes can reward easy, existing demand while starving the harder work of creating new demand. But the old hour-based model is clearly losing its magic. The billable hour had a lovely quality: it could contain almost anything. Whatever replaces it won’t be nearly so forgiving.