We've never considered the idea because we never thought of it.
The real question is whether one of those "free" games has a big enough player base that will adopt Hero Lab for one of the systems we sell. That requires that the player base of the "free" game must *also* play one or more of the systems we sell. There's no data available for that, so we'd essentially be taking a wild guess based on anecdotal evidence (at best) if we pursued the idea.
This is definitely something we should discuss in-house, since there might be a way to effectively leverage the idea somehow. I'm just thinking aloud regarding my initial concerns with the idea.
And by making it free or at a "special low price" it casts positive light on your company as giving back to the fans. and good publicity never hurts.
Thanks for suggesting this!