United Rentals Put 5,000 Reps Through AI Role-Play — Here's the 2.6% Uplift Behind It

United Rentals ran AI-generated buyer role-plays with more than 5,000 sales reps, and Second Nature’s case study on the deployment puts a number on what the practice was worth: reps using the role-plays closed 2.6% more revenue than reps who didn’t, with the lowest performers gaining as much as 35.2%. The University of Houston ran the same platform through roughly 1,300 students per semester, treating it as a required rep in a sales-communication curriculum rather than a supplement to it.

The seven tactics Second Nature pulls from both deployments matter more than the topline number. “Microdosing” — frequent, short sessions instead of occasional long ones — is tied to roughly a 1% revenue increase per additional session completed. Managers matter as much as the tool: reps under high-performing supervisors saw a bigger lift, which an unnamed Second Nature executive attributes to managers translating role-play repetitions into live-call habits. The AI isn’t replacing manager coaching. It fails without it.

Second Nature’s own research backs up why the repetitions work. A July 15 post citing Dr. Coral Shachar argues traditional role-play triggers a stress response that routes cognitive resources away from durable learning, while private, low-stakes AI practice triggers dopamine and oxytocin release that speeds skill acquisition — the company’s stated basis for claiming reps can reach in a single day what live role-play training takes two to three months to build. Three weeks before the case study published, Second Nature had already shipped Video Avatars — nodding, eye contact, lip-sync — to close the gap between simulated and live calls further, giving existing customers 6,000 free practice minutes to test it.

The takeaway for sales leaders isn’t “buy AI role-play.” It’s that the uplift only shows up when managers are trained to use what the reps generate, and short, frequent sessions beat occasional long ones.