Are you sure you want to leave? :-)
You can also show the popup, just before someone tries to leave your blog. You can offer them an incentive to stay, like a special report, or even just remind them of the benefits of staying on your site.
As you notice, this popup has different dimensions than the "on entrance" popup. It also appeared "on before exit." Plus, it has a different background color.
You can show totally different popups, with totally different settings on each post or page of your blog from a single installation of 1-Minute List Builder.