Brands Are About to Rewrite What They Expect From Agencies

By summer 2027, AI capability will stop being something an agency can charge for. Already, we’re seeing the economic value of this feature decline, since brands can connect Claude or ChatGPT to their own ad accounts through an MCP server and check claims themselves. However, what a brand will still pay for is harder to copy: knowing what to change, proving why, and owning the result.

We asked four people who run agencies, build tools for them, or work on the brand side to describe how agencies will run come summer 2027. Their answers ran the gamut from: the pitch, the kickoff, the weekly numbers, the account handover, and the budget call.

“Show us, live.”

The credentials deck is losing its power to differentiate. Erin Regan, fractional chief growth officer at the marketing agency Brandon, expects brands to change the format of the pitch itself.

“By summer 2027, CMOs will stop asking agencies to describe their AI capabilities and start asking to see them in a live working session: a real brief, the actual tools, and the people who use them every day, all working through a problem in real time,” Regan says. “Agencies that have only gotten faster will struggle to keep up. Agencies that have changed how the work gets done will win.”

This moves the pitch asset from the deck into the workflow itself. If your team can’t work a brief live, that gap should be a priority to close.

“Count every sale once, and agree on it at kickoff.”

When you pass the live test, the second expectation meets you in the contract. Meta Ads and Google Ads can each claim the same conversion, so the brand counts one sale twice and sends budget to the wrong channel. Avery Max, Summer’s co-founder and CEO, hears about that gap every week in conversations with agencies, and he expects brands to close it on day one.

“AI can’t answer without a clear definition, so agencies and brands agree on it up front and write it into the contract,” Max says.

The definition doesn’t change how Meta or Google credits a sale; each platform keeps its own attribution rules. What it decides is which claim your reporting accepts, ensuring a sale counts once in your numbers and budget follows the channel the contract says drove it. For your team, metric definitions become a contract item with a named owner.

“Show us where every number came from.”

Definitions settle how a sale is counted. Next, brands will want to know where those numbers came from, because an AI-generated answer always sounds certain regardless of correctness. A number pulled by an agent can be technically correct and structurally misleading, as I told Ad Age, so the marketer who presents it to a CFO carries the risk personally.

Brands will ask one question about every figure you present them: where did this come from? Not a methodology page, but a per-answer audit trail, a short record tracing the number on the slide back to the platform data behind it. If you can answer in one step, you keep the room. Every number you can’t trace costs you twice: once in the hours spent rebuilding the math, and again in the trust the next number arrives with.

“Our context belongs to us.”

Once the numbers are trustworthy, the brand’s accumulated context becomes more valuable. Mark Rentschler, head of marketing technology at Agiloft, sees agency offerings moving from running tools to building them around each brand’s own systems.

“If you hire an agency to help with lead management, the implementation would include not only documentation of CRM and marketing automation architecture, but also an AI model trained to interact with those systems and package up leads for sales in a clear, consumable way,” Rentschler says. “Everybody has access to AI tools and features, but the biggest challenge is knowing how to train them for your specific use case.”

Brands will ask a pointed question: if we leave, does all of that come with us? The answer should be yes. The brand’s data, definitions, and account history transfer, while your team’s skill at using them doesn’t. An agency that says no is telling the brand its only hold on the account is the exit cost.

“Tell us which idea deserves the budget.”

The four expectations above strip away everything an agency used to hide behind, which leaves the question of what brands will still pay for. Andreas Eisermann, founder and CEO of the marketing agency GLAD TO BE, gave the cleanest answer we collected.

“Agencies won’t win by producing more with AI,” Eisermann says. “They’ll win by knowing which idea deserves the budget and connecting creative and media decisions to real sales. Creative judgment and accountable growth are what clients will still need an agency for.”

Add the five together and the economics of the work change. Production is cheap now that AI handles operations for marketing agencies, capability claims are checkable, and context leaves with the brand whenever it wants. What remains on the invoice is the part a brand can’t produce, check, or carry away: the call on which idea deserves the budget, the proof behind it, and someone who stands behind the result. Through 2026, agencies billed for doing the work. From 2027, they’ll bill for being accountable for it.

The fastest way to test whether your team is ready is to ask your own data any campaign question and see what comes back as proof.

Frequently asked questions

How should an agency prepare for a live working session?

Pick a real brief, use the tools your team runs every day, and bring the people who run them. The session only goes wrong when the daily workflow and the pitched workflow are two different things, which is the gap to close before anyone asks.

Does one shared definition stop Meta Ads and Google Ads from double counting?

It stops the double count in your reporting, not in the platforms. Each platform keeps crediting sales by its own attribution rules, and the definition decides which claim your numbers accept, so the remaining attribution calls get made once at kickoff instead of argued every week.

What should the measurement part of an agency contract cover?

The definition of a conversion, the attribution window behind it (how many days after a click or view a sale still counts), which source counts as the number of record when platforms disagree, and who keeps those definitions current.

Can an agency stay hard to replace if the brand’s context is portable?

Yes, because the brand’s context and the agency’s method are different assets. The brand takes its data, definitions, and history. The agency keeps how it reads them and what it does next, which no handover file carries.