When I first heard of uBeam and their goal I did some back of the envelope calculations. Setting aside the safety issues (which are not settled, start-up CEO claims to the contrary), the biggest problem is conversion efficiency. Using some optimistic assumptions about conversion efficiencies and beam steering accuracy, I don't see how they're going to achieve even a 10% net conversion efficiency at useful distances. So I've been very skeptical about the prospects of success, yet I am very interested to be proven wrong on some of my assumptions. But the longer this product launch gets stretched out the more skeptical I get that this will ever be a product that anyone would want to buy. This is starting to feel like Theranos- the time has come to put up some real evidence.