Old question I know....
There's a saying among those in direct mail and sales design...
"Ugly Sales"
It is often the case that a design which is less "high-brow" has a better return on investment (ROI).
It's really not about the product. It's all about the audience. If the target audience is more middle-class or just a broad, general demographic not specifically separated by financial means, then a perceived lower-rate, less formal, more "clichéd" design has a tendency to "sell" better.
To be clear, I'm a designer, not a marketer. So, I don't have access to solid statistical numbers to back this up. However, I am responsible for the control piece for many of my clients and they all range from "ugly sales" to more "luxury" design. And all that is based upon the target demographic. Some "ugly" pieces are reprinted every year and still get a great ROI. "Ugly Sales" doesn't typically work for higher end audiences. But barring that, it can work for almost all other audiences from opportunity seekers, to self-help, to security and health.
It's somewhat like intentional typos. They can be used to convey a less "slick and formal" atmosphere making the product or service seem "approachable" to everyone. Same theory that's behind some horrid local tv commercials you may see as well.