A Kickstarter project for a device you wear on your wrist, but that needs a smartphone to do anything really interesting, has raised more than $5.3 million in eight days. This is this far and away the most anyone has ever raised on Kickstarter, and it’s happening – with a gadget in a category that has a pretty dismal track record – at a sales pace that would make even Apple sit up and take notice.

Mind you, Pebble, “The E-Paper Watch” looks very snazzy. At $115 (only 200 were available for $99, and it will retail for $150 when it goes on proper sale) it’s not terribly expensive. And there is a bit of the Kickstarter effect for things that get lots of favorable press: It’s great to get an insider deal and to get in on the ground floor on something cool. And to risk nothing: If the entrepreneur’s funding requirement isn’t met, you don’t get charged a penny.

Within two hours the people behind Pebble got what they asked for: a measly $100,000. By the time the funding round closes on May 19, they’re on pace to have more than $30 million in orders.

All this for a product that doesn’t exist and – see above – requires a smartphone to do anything interesting.

But therein lies the secret of Pebble’s apparent success. We don’t need something for our wrists that does anything really amazing, because we do have our phones. But we may want something that makes that smartphone we already have a little more convenient to use. The Pebble allows you to see text messages and information at the flip of a wrist, without reaching for your phone. Do not underestimate the power of incremental convenience: How many of us constantly reach for our phone, or always have it in hand, just to keep up with the data overload, most of which doesn’t require our immediate attention?