Well yes, you could start a million. But how many of those companies would
last more than 6 months? :-)
I thought the deflation of Bluetooth hype was already starting in a pretty
serious way. Lots of hedging from member companies about how
big/expensive/power-hungry Bluetooth devices will be, no-one really
committing to shipping products, etc.
I also had the impression that Bluetooth only delivers a communication
channel, and has very naive notions of user authentication. I was
tangentially involved in some discussions about ad hoc conferencing that
envisioned pairwise manual authentication: i.e. for each pair of devices in
a conference, each user would be presented with a dialog box asking whether
it was OK to trust the other party. That also seems like something you'd
have to fix to do wearable e-commerce.
[I will be happy to be corrected if I have this wrong. I don't claim to be
an expert in this area, just an interested bystander.]