My peer group used Glass for active stuff. We took video of ourselves rollerblading, playing hockey, doing OCRs, playing with our kids. The battery was never good enough to record that long. It would become physically uncomfortable because the battery would become hot against your temple.

Everybody wanted them. Do you remember 'car phones'?

Everybody wanted something they could hold in their hands to talk to other people.

Nobody wants a 'computer on their face' which looks like a computer, and doesn't do much.

Snapchats glasses fit perfectly with the Snapchat experience, which on the whole is nothing like most other chat apps, and nothing like Google.

Snapchats glasses are focused on sharing 'serendipitous moments of irreverence among young people' - and that's exactly their brand promise.

I'm not sure if these glasses will become mainstay or grow to be something bigger - but everyone in tech should take note of how Snapchat is doing this.

It's brilliant. Nobody in the Valley - save maybe Apple - even comes close to this kind of smart consumer marketing.