Do you mean how did I decide which market to target or how have I marketed to those people? Either way, same answer. I choose a market/community I was already part of and understood.

My mistake was not doing that the first time. I knew there would be a market for a headless browser service in the client-side javascript framework community. I tried to expand it to also include testing and screen capture. I didn't understand those markets. I wasn't able to offer value there, but trying prevented me from offering max value to the market I did understand.