JapanTechnology and telecom2024 – ongoing

Mercari

Ellie internal generative AI tool for employees

Mercari's in-house generative AI tool Ellie reached 75% monthly usage among staff in late 2024

WorkingCompany's own claimOfficial ↗

Problem

Mercari, a Japanese marketplace company with about 2,000 employees, wanted staff to use generative AI in daily work. It needed to know whether tools were actually being used and whether people kept coming back.

Approach

Mercari built Ellie, an internal generative AI tool, and tracked monthly usage and 30-day retention. It ran 19 Lunch & Learn sessions between September and December 2024 with 1,700 total participants. About 350 people joined an AI channel run by the article's author.

Results

61% to 75%Ellie monthly usage rate between July and December 2024, as reported by MercariCompany's own claim[1]

above 80%30-day retention, the share of members who returned to Ellie, as reported by MercariCompany's own claim[1]

Takeaway

Mercari measured use through a usage rate and a 30-day return rate rather than license counts.

Sources

Taking Full Advantage of Generative AI to Maximize Value—AI Usage and Initiatives From July to December 2024 at Mercari
Mercari19 Mar 2025Company publication

Source summaries

[1]Mercari19 Mar 2025

A Mercari employee reviews AI use at the company from July to December 2024. Ellie's usage rate rose from 61% to 75% and 30-day retention stayed above 80%. The article does not state when Ellie launched.

Full details are in the original sources.

Added 2 Nov 2026 · Updated 2 Nov 2026