Our site is getting dinged pretty hard on “cookieless” domains. For example:
Home page is www.domain.com
We use the following CDN domains:
graphics.domain.com (images, media, graphics, etc)
images.domain.com (static images associated with our customers)
video.domain.com (video files served up for our pages)
All of the CDN domains are Akamai, with a dedicated server in our data center for origin, except for the images and video domains, which have Akamai NetStorage as origin.
We set a cookie on domain.com (not www.domain.com), so obviously all of our CDN domains are “cookied”. We have to set this cookie domain-wide, since we have multiple hostnames under domain.com (such as ww1.domain.com, ww2.domain.com) which are used for our A/B testing, etc, etc.