The skill I built for my product turned out to be sellable on its own

A developer building Xedge, a tool for finding the right AI stack, discovered that the manual service of providing AI stack recommendations—which they had been doing for free—is a sellable skill. They are now offering 'AI stack research and setup' as a freelance service while continuing to develop Xedge, highlighting that expertise gained during product development can have its own market.

For the last 4 months I've been building Xedge — helping people find the right AI tool stack for their specific goal. This week, needing to cover some short-term costs, I realized something: I've been doing this exact service for free in DMs for months. Someone asks what they're building, I figure out their AI stack, I reply with the breakdown. That's a sellable skill completely separate from the product itself. So I'm testing it directly — listing "AI stack research and setup" as a freelance service while XEdge keeps compounding in the background. The lesson here: sometimes the tool you build to solve a problem at scale has a manual, sellable version hiding inside it. Don't assume the only output of months of building is the product itself — the expertise you gained along the way often has its own market. Anyone else found unexpected income inside a skill they built for something else entirely?