It turns out that my work on Watermark was a complete waste of time. After I released it, everyone told me that Aperture has a built-in watermark feature (which I was completely unaware of), hidden in the export format window. If I had known, I wouldn’t have released it. I most likely won’t release any future updates since it landed with such a thud.
Man, that sucks.
I think that there are still lots of people out there (those who aren't advanced enough to be using aperture) who really value this.
I work for a photo site that offers watermarking and we get a lot of good feedback on it.
So, hopefully you can still find some users 😉