Re: And if there is
Those 200 people would jump at it, and course it would also require online services to adopt it as well.
I guess that unlike some 'adoption dilemmas' (i.e, I'm not buying this gizmo until it's supported by devs, devs won't bother supporting it until people have bought it) there's a low cost of entry (some time, possible a small hosting fee) to early adopting users.
I'm assuming as well that the likes of Google won't be interested in this, but the hundreds of smaller services and retailers we interact with online might be.
(And personally, I'd be happy in principal for smaller online companies to have access to market reports derived from my anomynised data - otherwise small companies find it hard to compete on quality, service and value because they are at a disadvantage in terms of market data compared to Amazon et al. )