Justin was already using a comparable newsletter tool and had the familiar side-project impulse to build something better. Rather than start immediately, he set himself a six-month deadline: if the itch to build his own version hadn't gone away by then, he'd start working on it. A separate, later HN comment (s3) frames the same decision as picking a sub-niche (Markdown, a REST API, developer-adjacent functionality) he was personally well-equipped to build. Buttondown's own "pricing page driven development" post (s10) independently confirms the positioning: an API-first alternative for people who don't want to spend all day inside Mailchimp, echoing this record's own framing of wanting 'a better newsletter tool than Mailchimp.'

“I was using a similar tool and thought to myself “man, I could make something better than this.””

Buttondown started as a self-hosted tool Justin built only for himself, then showed to a few friends, who pushed him to turn it into something more than a personal script.

There was no formal sales motion. Per a third-party interview where Justin is directly quoted, people he showed the self-hosted tool to simply asked to pay for it. A separate founder-authored Q&A puts the first paying customer at roughly a month after he started using his own tool, in the rough neighborhood of the record's own 14-day first_customer figure, though not an exact match.