I think it's critically different from advertising because the art is also the product itself. You're meant to enjoy the art for what it is. An ad on the other hand, is meant to encourage you to buy a separate product; this can be effective even if you absolutely hate the ad.

A more apt comparison would be a company giving out free samples. If you get a free sample of a delicious new cheese brand, you might talk about it to others and raise their public profile. But that only works if the cheese is delicious. On the other hand, an ad might just rudely scream "KRAFT MAC AND CHEESE" at you for twenty seconds in hopes of subconsciously leading you to buy their product when you see it in the store later that week.