Pop up windows are sort of a mini browser screen that appears along with the main page that you are downloading. When it comes to pop up windows, the general public just seems to hate them. Once again, anything that can slow down your web site is not a good idea. If a customer sees a pop up window, he or she may avoid coming back again. Why do anything that may hurt your traffic? Remember, keep it fast and simple.

 can index them, the pages must be interpreted into HTML and can lose much of their content.