Many are guessing that the product will fail because it has no user monetization built in. That would have to be added through advertising or marketing through the apps.
Failure at the marketplace is always a possibility with a new product. But a focus on near-term profits here misses the point: The technology behind Google Glass isn't going to fail. Human nature won't let it. The voyeuristic tendency to record every detail of our lives and to have easy access to all of that data, our own and others, isn't going to go away and devices that make the experience of recorded lives easier are going to proliferate.
In 1889, the legendary composer Johannes Brahms sat down at a piano and recorded a snippet of himself performing his Hungarian Dance No. 1, on an Edison wax cylinder. That recording is almost unlistenable to us, crude or torturous, but it opens up a tantalizing glimpse into the actual sound of the 19th Century.Musicologists and audio technicians have fussed over that recording for decades now, in the last few years actually succeeding in extracting enough information to recreate Brahms' actual piano playing (in a MIDI-facilitated performance available on YouTube) in a way that appears plausibly accurate. And the book is still not closed. New technological advances will no doubt extend our ability to extract more and more information from that one poorly preserved moment. As musicians, as musicologists and historians, and most importantly, as human beings, we are drawn to that tiny crack in the black fence of unknowable history like a vine seeks out the sun. Prior to 1889, our knowledge of musical performance was limited to musical scores and other composer instructions and descriptions of performances. The details were opaque, and consequently the whole picture of any historical moment poses a puzzle. Each generation solves the puzzle anew according to contemporary concerns and shifting philosophies. History becomes an animation of the here and now, projected onto the blank screen of the past.