Look at the Class of 2016 at Gliebers Dresses ... fewer new items than surrounding years and poor productivity of those items.
You know who gets blamed?
Sometimes marketers get blamed ... conversion rates fall because new items perform about $2.0 million worse than they should and it becomes a marketing issue.
These aren't marketing issues ... these are merchandising issues that marketers get blamed for.
As a marketer, you MUST measure this stuff. You have no choice, your job depends upon it. If you don't measure it, somebody will eventually blame you for having miserable conversion rates ... it'll be your fault.
P.S.: If you don't like this stuff, then read how 28% of traffic is not human ... I'm increasingly confident that all of this digital stuff is going to turn out just fine.