A common fallacy in publication, and in music to be honest, is that artistic expression does not sell. I'm not here to give you polls, facts, and figures, but instead I want to give you a very tiny sampling of the differences between the two forms of expression so you can read them and see which appeals to you. I don't want it to appear as if I'm punching up or down at other authors; I'm going to use music lyrics to show you the difference in form.
The thing to remember here is that the more artistic song lyrics were bestsellers and so were the songs that were written to market. Neither style is right or wrong, because both styles are simply geared toward different audiences.
A very brief note about the four selections: I'm writing this really fast, so I haven't explored all of the variations on this musical theme; however, the four selections are all men. Many, many female artists will fall on either the artistic or written to market side of the fence (see Beyoncé for artistic form as opposed to Donna Summers' 1980s and 1990s catalog for the lyrics to some of her highly marketable works).
The reason this sample is all male is because it is easier to search "boy bands," whose songs are almost entirely, without question, written to market.
As you read these, think about your own prose. This is, sort of, a self-test for you to take in your head. Ready? Here we go:
Dig if you will the picture
Of you and I engaged in a kiss
The sweat of your body covers me
Can you my darling
Can you picture this?
--When Doves Cry, Prince
Written to market:
Oh, I just wanna take you anywhere that you would like
We could go out any day, any night
Baby, I'll take you there, take you there
Baby, I'll take you there
--Kiss You, One Direction
Well you're dirty and sweet
Clad in black, don't look back and I love you
You're dirty and sweet, oh yeah
Well you're slim and you're weak
You've got the teeth of the hydra upon you
You're dirty sweet and you're my girl
--Bang a Gong, T. Rex
Written to market:
For all the times that you rain on my parade
And all the clubs you get in using my name
You think you broke my heart, oh, girl for goodness' sake
You think I'm crying on my own. Well, I ain't
--Love Yourself, Justin Bieber
So now that you have this information, what do you do with it? Again, think about your own prose and decide which kind of writer you are. In determining your style, you can better find and market your work to the appropriate audience. There is a market for artistic expression, and while you might have to work a little harder to get noticed, you can make your work artistic and marketable. Don't let anyone tell you otherwise.