The generic, and undoubtedly poor customer service that you come to expect from the mass market manufacturers.
It is the niche houses that offer better customer service, particularly regarding samples. You could argue that this is due to the fact that they earn far higher margins per unit of output, but they simply adhere to their clientele that are unquestionably more knowledgeable and selective when it comes to new product launches.
I'd guesstimate that a significant number of purchases of Diesel, Armani, Boss are blind buys by girlfriends / family / friends for birthdays and commercial occasions like fathers day.
The likes of Amouage, Creed, Guerlain deal with a different type of customer, that is often more knowledgeable than the sales assistants.
I'm a complete novice compared to the majority of members on this forum, but when I tried to speak to a sales assistant on Creed's batch numbers, neither he, or the departmental manager had the slightest idea what I was talking about.