CodeCanyon - Ninja Popups v1.5 for WordPress | 7,41 MB
Ninja Popups combines a professionally designed popups to convert visitors on your site/blog into taking an action whether its subscribing into your newsletter, offering a discount/coupon for leaving customers, or locking content until they share you will increase your subscriber count and social signal of your site/blog.
DEMO:
http://codecanyon.net/item/ninja-popups-for-wordpress/3476479