I've never run a business and don't know much about these things, but I'm sure part of the reason why Yoox beats Mr. Porter on prices is because they don't have garment measurements and poor product descriptions. You'd have to pay people to do that extra work, and that extra cost gets added to their prices. Yoox works and is successful for now because a huge, hyper-efficient warehouse is better for cost savings than reducing return rates.
I think that's right. I also think that Yoox sources its inventory differently. My guess is Yoox is buying large lots of merchandise, probably without knowing specifically what they are getting; e.g.: here's a lot of 100 shirts from supplier x. They get it really cheap, obviously. But they are not spending time having buyers decide which items to carry, as Mr. Porter is. They buy cheap, in bulk, then they get it on the site as quickly as they can. Very lean operation, I'll bet.
Also, not having B&M stores helps with costs, of course.
But this is not the first time I've heard of customers being rejected, and not just from Yoox. On the other hand, I don't know how anyone can be confident of what they are getting when they order from Yoox, due to their vague descriptions.
This happened to me, as well. They sent me a nice email asking if there was a reason I've made so many returns. I actually have not purchased from them in at least a year. But I noticed I don't get the DealFlyer anymore. STP is not quite as bad as Yoox, but they also suffer from not giving enough information, not to mention sending out merchandise that is really beat up.
But I don't know how you can sell clothing online without expecting lots of returns. LA Guy cited 10% returns for B&M vs. 30% for online; that's because you can actually see and try on the merchandise in person in a store. I don't know that there's a level of description on the web that would narrow that gap much; although whatever it is, Yoox is far from it.