When appointing a media agency, the conversation can often come down to one simple question: how much money will you save us?

It is an easy promise for an agency to make – and an equally easy metric for a client to focus on. In some pitches, cost savings can become the central proposition: hand over your media account and receive a guaranteed chunky percentage off your bill. 

We understand the appeal. But we don’t think it’s the right way to choose a media partner. According to AAR’s Lead Media Consultant and Partner Hannah Astill, that approach risks overlooking what really determines the value of a media partnership. 

“We’ve always believed that efficiency and effectiveness have to be assessed together,” she says. “Making a saving means very little if it comes at the cost of the media actually working properly. If done right, it can give meaningful competitive advantage.” Media, Hannah argues, is where that trade-off shows up hardest, because it’s the part of the market where price-led selling is most aggressive and most commoditised.  

That thinking is what led AAR to build the AAR Index – a framework for assessing a media agency’s value across five metrics, not one. Price will always be important, but there are four other metrics that should be taken into consideration alongside it to give a true index of value.

The five metrics, at a glance:

  • Pricing – investment efficiency 
  • Commercials – investment effectiveness 
  • Contractual governance – investment due diligence 
  • Effectiveness framework – investment attribution 
  • Creativity – investment multiplier effect 

Here’s what each one means in practice, and why Hannah believes a client needs all five, not just the first. 

1. Pricing: Investment efficiency

How cost-effectively is media being bought, and is that price actually transparent? It’s the metric every agency leads with, because it’s the easiest to put a number on. But Hannah is quick to point out its limits: “A rate that looks sharp on the surface and opaque underneath isn’t efficient; it’s just hard to check.” Price matters, she says, but it’s one fifth of the picture, not the whole thing. 

2. Commercials: Investment effectiveness

Beyond the media rate card sits the shape of the relationship itself: the remuneration model, the fee structure, the strength and resourcing of the team, the tools behind the account. “This is the part I think gets missed most often,” Hannah says. “You can negotiate a brilliant media rate and still be badly served here. A cheap deal with the wrong team on it isn’t a good deal.” 

3. Contractual governance: Investment due diligence

A weak contract can still undermine a strong price and a strong team. “I see this constantly; loose, ambiguous clauses that read fine but don’t actually hold an agency to account,” says Hannah. “It’s the metric nobody thinks to ask about, which is exactly why it belongs on this list.” A proper contractual audit, she says, is what protects everything negotiated elsewhere, and routinely turns up value that would otherwise sit unclaimed. 

4. Effectiveness framework: Investment attribution

What is the agency actually being measured against, and does that reflect what a business needs to prove internally? This, Hannah argues, should never be handed to an agency as a template to fill in. “The partners I rate most highly are the ones who come to the table with a framework they’ve built specifically for you, unprompted,” she says. “That’s usually the sign for whether an agency can properly evidence its impact and business case for further investment, or whether it’s just reporting on what’s easy to measure.” 

5. Creativity: Investment multiplier effect

Media and creative are converging rather than sitting in separate lanes, and Hannah sees a media agency’s creative DNA as one of the most underrated things clients should screen for. “The best media partners have real creative capability; in-house creative or strategy talent, or a genuine willingness to work hand in glove with your creative agency, rather than treating media purely as a distribution and performance exercise,” she says. Done well, this is the metric that turns media from a cost line into growth. 

How AAR puts this into practice

Naming five metrics is one thing; scoring a shortlist of agencies against them consistently, without defaulting to gut feel, is another. According to Hannah, that’s where the real value of working with AAR on this sits. 

“It gives clients a professionalised, structured way to compare agencies that goes well beyond who’s cheapest or who they liked best in the room,” Hannah says. “It means the decision you make is one you can actually defend, on effectiveness as much as on cost.” 

If that’s a conversation you want to have about your own media agency setup, Hannah would love to talk it through.