I hope I’m misreading this situation…
A firm called Taxi Promotions UK is paying London cabbies to talk up their clients in what appears to be an ill-conceived stealth marketing campaign. (Full article from the International Herald Tribune.) Cabbies get free vacations and other rewards in exchange for promoting them to unsuspecting passengers.
But… as far as I can tell, there is no requirement or training for the cabbies to disclose that they are paid salespeople, not "ambassadors" as they call themselves. They call it "word of mouth" — but it’s not, it’s unethical shilling.
I hope that the cabbies refuse, that clients learns the basics of word of mouth disclosure, and regulators take a good look at this nasty invasive procedure.
Let’s review: Word of mouth marketing is honest conversation between people who share what they love about a product. Stealth marketing is paying people to lie for you.
If it is disclosed – good, if not – bad.
Read the WOMMA ethics code.