| The artistic license is not the one for perl, it's the one for "real" artists, like poets, musicians, authors, architects, etc., who gain the license when they begin to create.
When an artist creates something, there's some type of inherant honesty that this is really what the artist thinks, believes, whatever. Art is outside commercial value, and when an artist makes a point for money (i.e. commercial endorsement), they can no longer be trusted for complete honesty, and are no longer artists. They key point is that it must be for an exchange of goods/services or money, an honest really "I like this" for free doesn't count against the artist (because we all have preferences).
Sample list of artists that have lost their license (if they even had one):
Kiss for Pepsi
Spice Girls for Pepsi
Jay Leno for Doritos
Johnny Lang for The Gap
Ridley Scott for Apple Computers (directed the 1984 commercial)
That actor on that commercial for that one thing, even if you never heard of him.
Krusty the Clown for The Canyonero
and so on
Though what the entities may create may be interesting (Ridley Scott, for example), it takes a lot to regain the license once it is lost. I haven't decided if it is even possible.
IMO, this does not apply to people advertising their own art. That is self-interest.
see:
Bill Hicks
The difference between the message that an artist sends and an advertisment is, for an advertisement, an artist was presented with external influences beyond regular societal pressures. He/She was persueded with promises of riches and glory or whatever from an industry interested in making profit. Ideally, artistic folk are not in it for the money.
It can be assumed that Ayn Rand beleived what she wrote or believed that she had a good reason for what she was writing. Walt Whitman as well. I'm not saying an artist can't lie, but that decision is theirs and theirs alone. However, Ridley Scott may or may not believe that Macs are the best computers, but that's irrelevent, because he took money in exchange for promoting a person, place, or thing. I'd like to think ideas are different, but I'm unsure. | 
