The popup you wrote had a humanizing effect. It's not just a faceless piece of software anymore. It's a a genuinely nice guy who built a cool product and wants to get paid.
As a concept, people know that there's a real person behind every application. But it's not until moments like these when they're actually confronted with that person. Much less offered a deal for trying to rip them off.
I think that the early shareware game days did a good job of this and I miss it. Instead of a "Click this link to purchase" you got a message from, usually, the sole developer or small team of developers. It was very humanizing and it was great.
The message would thank you for trying out the game. It would usually talk about how the game was awesome and what you were missing out on. It was clearly genuine. You didn't feel like you were purchasing something from some giant company trying to sell something. You felt like you were supporting some people who were passionate about the art they created.
I miss this about games and think it may be the reason that I've sort of stopped playing the big titles after 25 years of non-stop gaming. I find myself much more drawn to independent developers on the mobile platform or the wonderfully simple and innovative games from small teams.
As a concept, people know that there's a real person behind every application. But it's not until moments like these when they're actually confronted with that person. Much less offered a deal for trying to rip them off.