A version of this article originally appeared in my Forbes blog. I thought it might be useful for RSR’s readers as well. And most importantly, I’m VERY curious to hear your thoughts too.

In Miami, a new version of “The Design District ” is rising out of the ashes of the old Design District. This four-block-square area (give or take a block or two) is the new home to the highest of high end luxury retailers. Louis Vuitton, Christian Louboutin, Lanvin, Hermes, Tom Ford and Bvlgari are just a few of the somewhat stunning array of stores opening up.

The surrounding area, while up-and-coming, in no way holds the target demographic for these stores. In fact, it’s not clear exactly where those people live or visit from. And 8.3 miles away sits the venerable Bal Harbour Shops, notable for having the highest sales per square foot of any mall in the US, and ostensibly the world. Still, the Design District construction marches on.

I thought this clustering of high-end stores was something of a singularity until I visited Barcelona. Pàsseig de Gracia is the home of many of the very same shops. The surroundings are a bit different – people do actually live on the avenue, but the stores are the same.

And then there’s the model of saturation: the Michael Kors store. Of course the brand has a presence on the Design District and Pàsseig de Gracia. It also has a store in the Miami airport and unveiled a brand new shop on Carnival Cruise Lines’ ship Allure of the Seas (to name just two).

The ride through Barcelona left me in complete befuddlement. How can you have commoditized luxury? Isn’t that an oxymoron? Certainly the luxury goods market has been hot, but there’s a growing bed of data indicating that the market is flattening out a bit.

The question was answered to some extent in one of my favorite blogs, The Business of Fashion. The blog talks about the influx of wealthy Middle Eastern visitors to London pre-Ramadan. The sales numbers for these shoppers are rising sharply, up 43 percent for last year’s comparable period. That’s not flat at all! And the money spent by each shopper is significant. Visitors from the US spend an average of 512 pounds each in June. Visitors from Qatar, at the other extreme, spend an average of 1432 pounds!

The article goes on to explain what this discerning luxury shopper actually does:

“Our international customers are incredibly discerning and clued-up on product. They are looking for one-off pieces, limited editions or bespoke items, and are prepared to pay a higher price point for this level of exclusivity, ” said Shadi Halliwell, group marketing and creative director of Harvey Nichols. This season, the department store is targeting this consumer base with exclusive products including an 18-karat gold-plated handbag by Mark Cross and a pair of sunglasses by Linda Farrow, estimated to cost $10,000. “

“One-off pieces, limited editions and bespoke items ” are the magic phrases. The highest-end customer really doesn’t want a sea of sameness. They have the resources to buy to the best. They want unique items. And, apparently they want unique stores. There’s only one Harrod’s. Selfridge’s flagship location is unique, and it only has a handful of satellite locations. Harvey Nichols’ has a few more stores, but seems to mostly cater to Middle Eastern clientele in those few outlets.

The question we need to ask ourselves is, “When does luxury expand to a point where it’s no longer interesting? ” “How many doors are too many? ” After all, the brands mentioned at the start of this article are also available in high-end department stores like Saks, Neiman’s and others. Aren’t analytics telling these brand managers that they’re reaching some kind of point of diminishing returns? Are they ignoring what the data is telling them?

There’s another lower-end chain that’s reaping the bitter fruits of building far too many stores: Gap announced it’s closing another 175 stores in the US, on top of the 200 it closed just a few years ago. Aren’t there lessons to be learned?

We’re dangerously close to market saturation. The luxury shopper isn’t thinking about convenience wherever he or she may be. She’s thinking about destination shopping, even if that destination requires rolling out the personal jet. We’ll test the theory and report on the sales efficiency of the Design District as it unfolds.

After this piece was published, I received an invitation from Bal Harbour Shops’ PR firm inviting me to meet with the current third generation head of the mall and take a tour of the place (even though I’ve certainly been there before). Unlike most other malls in the US, Bal Harbour Shops is privately held, and has been in one family for its entire history. I’ll let you all learn what his point of view is in a future article.

Still, I’d really love to get your feedback on my observations. Please send me an email with comments: prosenblum at rsrresearch.com. Thanks!