The idea of this have me a chuckle. Instead of worring about skynet destroying all of humanity, we should be worried about them constantly asking about our car's extended warranty.

Seriously though, a real life robot is more expensive to make and run than an online one. Plus, there's nowhere for them to put "permanent" content, they'd have to talk to us one by one, or start graffitotagging ads everywhere. Any robots they did make would be obviously robots, and we can avoid them. It doesn't scale the same way.