I'm in Palo Alto, California, where we came across a shop with a salesperson outside trying to persuade people to come in.

There's nothing unusual in that - except the salesman was on a device called Beam, a sort of virtual presence.

And when we went inside there were no staff, except for other disembodied "virtual presences".

It's a clever gimmick, and perhaps a taste of the future.

But would it work on a British High Street?

I'm not entirely convinced.

I'll have more from the West Coast on Friday's edition of Tech Tent on the BBC World Service.

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