they go hand in hand. You can't have one without the other (well ok, you can't make a profit without putting the customer first).
the trouble here is that this is not something that's black and white, and making a definite decision is not possible.
I believe a compromise is often present, sometimes it's us who make the compromise and prefer to make a client happy, other times it's the other way around.
Nevertheless, it's of vital importance to always strive to exceed or at least meet your customer's expectation as no customers = no profit.