Jquery bottom popup for my website to promote other pages

Hello I need the visitors to stay longer on my Image site, i want them to view more pages, thats the main problem. Im now thinking of a kind of popup at the bottom of the site, where the visitor is presented with 5-10 thumbnails half could be from the main category, the other half random. maybe a little like those pops we see here on freelancer. If you have other suggestions how I can get the users to stay longer and visit more pages, just post them. This is no big job, but if things are ok and the site benefits from the changes I need more work done. the site is build with plogger cms.