Some sites use popup window. This is particularly common in fashion sites such as DKNY and CK. I can't see anything good of this. Why they use popup window?

I think the reason for this is so that you can be able to continue shopping while looking at their products but i may be wrong.

I mean windows that pop up after clicking enter on the first page. All the main content is presented in the popup window. Is it for hotlink protection?

OOH I guess it's to make it more unique from other sites i also see no point in it but oh well what can we do they are multimillion dollar companies lol

Easy organise on site with popup? You see many shopping carts have popup when you click the image to view large. It's better than open the window.

The website I maintain has pop up windows but only for displaying a larger image from a thumbnail.

It doesnt popup multiple windows, each image gets loaded into the same window.