This would incentivize spam since a new posting would be guaranteed top spot until the next new posting displaced it. So people would be incentivized to always be posting literally anything to maintain that top spot. The terrible designs would multiply horribly as people competed to always be the one to have posted the newest design.
Agreed on spam, but if there's 100,000+ existing design listings on a product, there's a slim to none chance your new design being discovered by a customer, no matter how good your new design is. Unless of cause they do a specific keyword search, or pick newest from the drop down. Honestly I think most won't bother, since all the popular designs are already at their fingertips. So there's always upper hand for popular designs. I hope Zazzle can think of a viable solution to promote new listings. And also if you look at Zazzle app, there is no filter or sort option for Newest listings.
