For more information check "When the Cookie Crumbles" by Tenni Theurer and Patty Chi. The take-home of this research:
- Eliminate unnecessary cookies
- Keep cookie sizes as low as possible to minimize the impact on the user response time
- Be mindful of setting cookies at the appropriate domain level so other sub-domains are not affected
- Set an Expires date appropriately. An earlier Expires date or none removes the cookie sooner, improving the user response time