Disappointing experiences using VoiceThread

Hi everyone! I'm sure you know or have heard about collaborative tool called VoiceThread. Basically it is a media aggregator that allows people to post various types of media — a document, a slide presentation, a video, or a collection of photos—for group feedback. Viewer can add remarks by means of microphone, webcam, keyboard, or telephone. The resulting Flash-based animation contains the original media and the commentary on it.

I thought the idea of having interaction with my students using VoiceThread is great. In addition, students can discuss among themselves on a certain topic or project via VoiceThread. Actually I decided to try VoiceThread as one of the activities in my wiki (http://imk209.wikispaces.com/). I explained the concept in the lecture and tried to convince them the benefit they would derive. The result? Very disappointing. You can see my VoiceThread here (http://imk209.wikispaces.com/VoiceThread). Only two or three students (out of about 50) participated, but the commentary given is apparently without much thought. Actually the students told me they like the idea of interacting and collaborating through VoiceThread but they didn't participate because they were simply very occupied with heavy workload.

I would like to hear from other educators who have tried VoiceThread - good and bad/disappointing experiences. Maybe I can learn something from you.