Decent cash is being paid for one time appearance of logo on tv.
This could be speculation, and I agree that service guy might not be the best source ever.
In this case though we are talking about decades of assured cash flow towards the oil company by reccomendation of the car manufacturer. Now I don’t know how about you, but I would have been willing to spend some damn serious cash for having MY brand of oil recommended in to a type of an engine. Mostly because innocent souls would totally fall for it and buy my overpriced grease-goo 9000, even though other brands will do just fine.
Otherwise, service book wouldn’t have been containing specific brand of oil you need to use for your car, it would have just contained the specification.
My service book has two page commercial for Selenia oils in it. You think they put it there for free?