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.

Read more about robotics and artificial intelligence:

• Chatting with the bots

• Can a machine become an artist?

• The search for a thinking machine
• What does Facebook want with AI?
• Intelligent Machines - a special report