There are kiosks and ATM's that currently leverage Motion Sensors. When a person walks in the vicinity of or approaches the kiosk, the machine welcomes them and guides them on how to use the machine.

I hate it when that happens at the local department store, so i dont think i would approve of it just to get a soda. A quick google should find the info if you are so inclined. I'll be walking past a music display, and all of a sudden it will start playing music. Or in the toy aisle certain toys will randomly activate, usually scaring the crap out of me. And this has been proposed by the vending machine manufactures. I remember a news article on it.

Someday, people will come to realize that otherwise unwarranted noises *scare the $#!+* out of other people. Sound is actually a lot more effective stimulus than video, perhaps too much so.

If this machine were to begin speaking only after I inserted some change or pressed a button, then fine. Maybe I'm farsighted and need a little help. In any case, I believe that consumer interactions should be reactive, not proactive. I'll fight any advertiser who wants it any other way.

Bothersome machines like this, especially in retail outlets, have a way of suddenly and mysteriously ceasing to be annoying, and employees have a way of not noticing that the machine is no longer making noise and driving them mad.

Put less subtly, if it annoys the staff it gets unplugged.