Try this
Code:http://blog.tribulant.com/popup-plugin/wordpress-popup-plugin-launch/
Hi guys!
I've found a suitable solution for me. I have installed the "Ads by datafeedr.com" plugin .
In the settings all popup codes / layer codes can now be entered with the number of impressions and start / end date.
Recently I have just inserted the code "<php echo dfads ('groups = -1');?>" in the header of my WP theme.
That's it! Works perfectly!