If you scroll down, you will see a slideshow, "The 10 Best Countries for Women, 2012", under the header "Also on Forbes". When you mouse over it, it uses AJAX to load an ad. When you click it, the URL changes and ads surround the slideshow. As you page through the slideshow, the URL keeps changing and ads reload each time.
They obviously have AJAX figured out, as they used it to show an ad when hovering the mouse. Rather than use that technique to create the best possible slideshow experience, they have chosen to avoid it in favor of loading more ads more often.
Sad that such a respectable entity like Forbes would bend over backwards to bombard users with ads and make a sub-optimal browsing experience. I would absolutely support a law that banned ads entirely.