A reason, not the reason. I don't imagine these companies discount the sort of money that the NSA seems willing to throw at these sorts of problems. A sum that

A reason, not the reason. I don't imagine these companies discount the sort of money that the NSA seems willing to throw at these sorts of problems. A sum that will not be gained from what is, given the quality of the microphones and the maturity of the algorithms, a novelty item in other respects at the moment. If the technology matures, yeah, you'd want to sell it to everyone. (Actually you'd want to sell different forms of the technology to everyone, or at least different licenses, so that you could bleed them of as much money as possible.) But in its current form, and perhaps for some years after depending on how much of an edge you'd think it gave you in the market, you'd want to sell to rich customers who have a strategic interest in the technology and can give you some sort of decent return on your development costs.