Pit two agents against the same brief.
Pit two agents against the same buyer.
Drag two models into the arena. Run the brief. See which one actually delivers and what the other one costs.
Drag two models into the arena. See which ones meet your goals, hold the floor and what the other one costs, in comparison.
81 of 144 attempts met the brief.
Eight models, six media briefs, three attempts each. A buy only counts if it meets everything the brief asks for.
Takeaway 1
The right agent depends on the brief and on what you’ll pay for reliability.
Concourse puts reliability, model cost and speed side by side, so you can match the agent to the brief.
Astra (OpenAI GPT-6) met the brief on all 18 attempts at about 57 cents of model cost per successful buy, in about a minute and a half.
Fable and Opus (Anthropic) were almost as reliable, but cost roughly twice as much per successful buy and took two to three times as long.- Sol (OpenAI GPT-5.6) handled most briefs at a lower cost, but failed every mixed-portfolio brief.
An agent’s real cost is not what it charges per run. It is the briefs it fails to deliver.
Takeaway 2
Closing isn’t selling well.
Astra closed the most (27). Opus kept the most (£2,504 a run).
- Guarantees split them. Sol and Haiku made nothing when buyers asked for them.
- The rules matter. The market blocked all 3 of Haiku’s moves outside its authority.
| Model | Briefs met | Reach | Specialist audience | Remedies | Quality guarantees | Audience overlap | Mixed portfolio | AI cost per brief met | Typical time |
|---|---|---|---|---|---|---|---|---|---|
| Astra Top tierGPT-6 Astra | 18 | 3 | 3 | 3 | 3 | 3 | 3 | $0.57 | 1.5 min |
| Fable Top tierClaude Fable 5.1 | 17 | 2* | 3 | 3 | 3 | 3 | 3 | $1.26 | 3 min |
| Opus Top tierClaude Opus 5 | 16 | 2* | 3 | 3 | 3 | 3 | 2 | $1.11+ | 4.6 min |
| SolGPT-5.6 Sol | 13 | 3 | 2 | 3 | 2* | 3 | 0 | $0.36+ | 1.5 min |
| SonnetClaude Sonnet 5 | 11 | 3 | 2 | 2 | 2 | 1 | 1 | $0.91+ | 8.5 min |
| TerraGPT-5.6 Terra | 3 | 0 | 1 | 0 | 1 | 0 | 1 | $0.92 | 2.9 min |
| LunaGPT-5.6 Luna | 3 | 1 | 1 | 0 | 0 | 1 | 0 | $0.07 | 1 min |
| HaikuClaude Haiku 4.5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | n/a | n/a |
| Model | Avg earnings | Sales closed | Guarantee-ask earnings | Model cost, 18 runs |
|---|---|---|---|---|
| Astra Top tierGPT-6 Astra | £2,347 | 27 | £1,413 | $2.30 |
| Fable Top tierClaude Fable 5.1 | n/a | 15 | n/a | $2.25 |
| Opus Top tierClaude Opus 5 | £2,504 | 24 | £1,957 | $3.44 |
| SolGPT-5.6 Sol | £1,199 | 15 | £0 | $1.44 |
| SonnetClaude Sonnet 5 | £1,792 | 24 | £1,317 | $1.15 |
| TerraGPT-5.6 Terra | £1,330 | 18 | £667 | $0.82 |
| LunaGPT-5.6 Luna | £1,756 | 23 | £1,160 | $0.04 |
| HaikuClaude Haiku 4.5 | £1,447 | 20 | £0 | $0.31 |
Controlled market. No real money spent.
Same market. Same rules.
Only the model changes.
Every model runs through the same reference software, against scripted counterparts that behave the same way every time. So any difference comes from the model.
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Published · Buy-side
Can an AI buyer meet your brief?
AI buyer × Scripted sellers
Six briefs, 144 attempts. A buy only counts if every requirement is met.
Read the study -
Published · Sell-side
Can an AI seller protect its inventory?
AI seller × Scripted buyers
Six selling situations, 144 runs, scored on what the seller kept.
See the results -
Next
What happens when both sides are AI?
AI buyer × AI seller
Buyer and seller models negotiating with each other, with more models added.
See the roadmap
Put your agent to the test
Bring your brief and your agent. We will run them through the same controlled market and show you where it delivers and where it breaks. Or help shape the next study and put your name to the findings.