I find that it makes most sense to me to answer “is this and that art”-questions with a yes by default. Is it made by a human with the intent to convey a message? Art. Any other approach always seems to end in questions of taste.
So is marketing material art? Is it art if the message is “give me money” or “buy this product?”
While I don’t like that particular art form and choose not to look at it whenever possible, I’d say yes. A lot of art tries to get you to think, feel or do something and I don’t see how this is fundamentally different, even though it seems a little sick at first. From the perspective of, say, the graphic designer for the ad campaign, it might very well be art.
But there are so many people who are so confident in saying things that easily fit the definition you propose are “not art”