I gota go with Target's earlier premise that most folk only speakup if there is a problem (e.g. No news is good news)
From my own experience with T-Clock and poking through the logs.
It has been downloaded approx 60,000 - 80,000 times
Out of those downloads 24,000+ visitors have been to the T-Clock page of my site
Approx 18,000 - 20,000 of those were unique IPs (so some repeat business looking updates as it's a single page)
Out of those numbers I've received only about 100 emails most of which were suggestions for new features or complaints about removed features.
Out of those numbers, less than 5 people engaged in further conversation beyond my initial response.
Only 3 of those requested to be notified of new releases.
Out of close to 80,000 people that downloaded my 64-bit resurection of a cult classic program, less than 10 Emailed me specifically to say atta-boy/thank you!
Am I bitter? Hell no! that's just life ... I do it because I love doing it ... other wise I go do something else.
No feedback, is feedback ... other wise they'd be complaining like mad