Ever noticed that when you go into Selfridges, there are some brands you will find in there that you won't find in let's say Boots and vice versa?

That's designer clustering.

Notice when you go to somewhere like Croydon Shopping Centre, there's more betting shops then clothes stores? That the designer brands are only small counters in a Debenhams while they make up an entire portion of Westfield's Shepherd's Bush?

That's designer clustering.

Carnaby Street is a destination for all things high-end but your mother wouldn't even step foot there twenty years ago?

That's designer clustering.

It sounds snobbish - and it probably is - but it makes sense from a business point of view. Let's imagine you're in charge of development for a luxury brand such as Gucci.  You know your customer well - you know their socio-economic status, their disposable income, where they live, where they shop, where they work. You're thinking of opening a new flagship store in Central London but aren't quite sure of the location. Presented with two options, you review them and have to come to a decision: 

Do you open it in Marble Arch right next to Primark or Sloane Street across from Tom Ford?

Sloane Street of course, because there's where your customer base is most likely to shop. A quick look on Google Maps will reveal an interesting perspective on where Gucci currently have boutiques set up in Central London: