I believe the SD has sold about 400 units, but that may go up substantially if it gets manufactured in China rather than by hand. So 5,000 is a lot but, possible bans aside, it has real potential. For the time being I guess it makes sense just to explore and be ready to move but not actually move into anything large-scale yet.
Existing manufacturers might also be somewhat hesistant at the moment. On the face of it they would be silly to miss the chance of breaking new ground with such a good stylish design; whether you could cut a good deal I don't know.
It will be nice to have a non-cigarette looking product out there.
Also, I suspect the FDA might object to current hardware in terms of leaking
juice (combined carts and mouthpiece) so i am looking into this. Partly also to solve the problems of inconsistent juice flow and needing to refill so often or resort to dripping. I have one solution that works well but is not something i could easily make by hand. Am now considering a design change involving the atomiser too.