Joe Thomas's own recap of the Opentest-to-Loom rebrand dates the OpenVid launch, the direct predecessor of Loom, to late June 2016, and in the same post links the product name straight to its Product Hunt listing (producthunt.com/posts/openvid), which is the founder-documented evidence that Product Hunt was the launch venue.

“as an experiment back in late June.”

Vinay Hiremath, in a third-party as-told-to piece (not Joe Thomas's own words), attributed the launch's traction to actively answering questions and comments on Product Hunt in real time rather than treating it as a one-way announcement.

Joe Thomas describes one employee at Atlassian starting to record and share Looms five days after the June 2016 launch, and that same organization becoming, about four years later, the first company to buy a Loom license for every employee.

“Fast forward four years and they became the first organization to purchase thousands of Loom licenses”

Vinay Hiremath, in a third-party as-told-to piece (not Joe Thomas's own words), described staying personally active on Twitter, replying to anyone tweeting about the product, as an ongoing growth practice rather than a single campaign.