Your oldest FS that still produce sales

[Lemmy]

I've got about 600 freesites under my belt and while my income is within the range of your friend's example it's only because I keep on pumping them out. Should I stop making them money would quickly dry up (and I see evidence of that happening anyway).

Despite what some might tell you there is no snowball effect or critical mass, only hard work that never ends. Based on my own experience of course.