Have you ever paid too much for a beer? Matt Cortland has — and it has set him on a path to never repeat the mistake.
In Cortland’s case, his favorite drink: a pint of Guinness. After paying €7.80 for an Irish dry stout in a Dublin pub in early March, the 37-year-old became curious about the average cost of a pint across Ireland.
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To his surprise, the country’s Central Statistics Office had stopped tracking the price of the nation’s most popular beer in 2011. This led Cortland to the bold idea of monitoring the price himself.
Cortland — founder of an AI startup — turned to artificial intelligence to help him, including with a voice. He created Rachel with the ElevenLabs AI voice generation platform.
Made as a tribute to Rachel Duffy, winner of the British version of reality show The Traitors, and equipped with a Northern Irish accent, the voiced AI agent made more than 3,000 calls across the island, asking about the price of a pint of Guinness.
“I thought, ‘What if I just called every pub in Ireland and asked them naturally using AI?’” Cortland told Fortune. “I started pulling on that thread and kept pulling — and here we are.”
Using the data collected from thousands of calls, he then turned to Anthropic’s Claude to create the “Guinndex”, which he defines as a “live and dynamic” consumer price index for a pint of Guinness across Ireland. The tool also allows bartenders and consumers to contribute and update prices.
Now Cortland can see how the €7.80 pint he paid weeks earlier compares to the rest of Ireland. On Monday, the average price was around €6.01 (R$36) and the most common price was €5.50 (R$33).
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Diageo, the parent company of Guinness, did not respond to Fortune’s requests for comment. Beer prices are set independently by pub owners across Ireland.
AI models are advancing at an increasingly rapid pace, surpassing parameters that even the most sophisticated scientists considered beyond the reach of machines.
Many are frightened by the idea of a jobs “apocalypse” caused by AI, but others are using the technology to answer complex questions. Some have even used it to sell their homes.
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And while OpenAI CEO Sam Altman and Google President Ruth Porat believe the technology will solve the world’s most complex problems, like finding a cure for cancer, AI is also solving smaller — yet still important — questions along the way.
Human-like voice AI.
Rachel, Cortland’s AI agent, is one of a growing number of voice AIs emerging on the other end of the phone line. Data from voice AI company Regal showed that customers consider AI to be as trustworthy as humans.
Based on data from millions of calls with voice AI agents, people spend 14% more time talking to AI than they do to a human agent. They also give 22% longer answers, sharing details they would normally omit.
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Cortland said he has seen similar results. The conversations his AI had across Ireland showed that most people didn’t realize they were talking to an AI. Transcripts of some of these conversations, analyzed by Fortune, make this clear.
“The price of a pint of Guinness? Twenty-five pounds. But if you just come for a drink, I’ll do it for five,” a bartender at Doogies in Enniskillen, Northern Ireland, told Rachel.
“Look, it normally costs 6.20 [euros]but if you can’t afford it, we’ll buy one for you. We take care of it,” a bartender at Malzard’s Pub in Kilkenny, Ireland, told AI.
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While Guinndex has not yet caused a drastic change in prices, Cortland said he has already seen results. In one case, he claimed that a pub owner had reduced the price of Guinness by €0.40 (R$2.40) and then updated the information on Guinndex himself.
He hopes to replicate Guinndex’s success for other products — perhaps prescription drugs in the United States, where he’s originally from, or even a slice of pizza in New York.
For Cortland, the level of transparency is essential in a market where he has seen prices vary drastically — sometimes by almost €2 (R$12) — between pubs located literally less than 100 meters from each other.
“If you’re charging €11 for a pint of Guinness, that’s fine,” he said (the most expensive pint in Ireland is €11, according to Guinndex). “But people should know this information.”
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