e.g. http://www.yourdomain.com/popupfilename.html
Foreground or Background:A foreground popup is in your customer's face and prompts your users to act immediately upon entering your site. It is an extremely effective marketing tool. However, it can annoy your users when overused.
A background popup (a "pop under") is much less intrusive. They will only see it after they close down their current browser window. However, it is not as effective and your users may lose context of the relevance of the popup because they are no longer on your site.
Load on Entry or On Exit:Do you want this popup to load immediately when your customers visit your site or do you want to have the popup load only when they leave your site?
On Entry popups are good to get your customer's attention immediately.
On Exit popups are mainly used to catch their attention when they leave your site. You can use exit popups to survey your customers or sell other people's products.