The danger of designing something new is involving both designers and marketers and expecting them to agree. Most designers and marketers want different things.
Designers want to design something that looks good. Something that looks good should work better, says the mind of the designer.
Marketers want to design something what performs better. And they’ll use data and analysis to prove to themselves and to others what performs better.
And the dirty little secret is that the best design is not necessarily the best performer.
So how do you solve this problem?
You address it at the outset. The project manager, who should serve the role of mediator between the two sides on any disagreement, should lay out the goals of the project so that everyone understands them. And the decision to test multiple versions should be made. This gives designers a sense that they are designing for performance, and that performance will be measured.
At the end of the day, I am a marketer and am biased toward the marketer’s point of view. But the results of a performance test should tell you which design is best, based on which works better.