Marketing = UX…
There is a remarkable amount of overlap between modern marketing and UX. Marketing is more than advertising and sales. It also includes market research, which identifies what would be useful, valuable, and desirable to consumers. Modern marketing also participates in developing the products themselves, ensuring they meet their target “value propositions.” Marketers may test prototype products on consumers and provide feedback to development. All very much like user-centered design.
“Emotional design” and desirability have been parts of marketing long before UX got into it. Advertising, placement, and promotion are equivalent to UXers designing for findability, persuasion, and trust. The very word “conversion” comes from marketing.
Back in the 1980s, well before the web, there was a revolution in marketing, characterized by a shift away from “pushing” existing products onto consumers, to fulfilling consumers’ real needs through research and innovation. In this approach, the marketer is the “customer advocate” in the business. Sounds familiar, doesn’t it?
…Except for the Scale
The difference between marketing and UX is the scale of operations and units of analysis, with marketing concerned with more broad and abstract product features and consumer characteristics, while UX covers details down to each click and pixel. Thus, the two are neither redundant nor in competition with each other, but compliment each other. I don’t think you can say which is better for getting conversions or promoting user satisfaction any more than you can say whether finance or accounting are more important for handling money for the business. Both have a role.
Beware, Young Skywalker
I don’t think there’s a conflict between marketing and UX, but there is a conflict between the light and dark side in both UX and marketing. When seduced by the dark side, both marketers and UXers pursue conversions at the cost of a truly positive consumer/user experience. What you may see as a conflict between marketing and UX may really be a conflict between Dark Marketing and Light UX. However, there’s conflict between Dark UX and Light UX too. Some have used the Force of UX to persuade users of something they shouldn’t believe or earn their trust in something untrustworthy.
Better ROI?
Whether you’re talking marketing or UX, I believe the light side is usually better for most businesses in the long run. Usually. Most businesses. But not always for everyone. In certain situations the dark side will get you more money. That doesn’t make it right, however.
I’ve more on marketing, UX, and ethics at A Man of Wealth and Taste. For a non-technical intro to modern marketing, I recommend Kotler on Marketing.