The iPad enables Safari's pop-up blocker by default, causing the browser to prevent Web pages from spawning secondary windows. Safari doesn't make it obvious that it blocked a pop-up, so the block might go unnoticed. However, some sites detect pop-up blockers and request that you disable them for the site to function fully. IOS 7 includes an option in the Settings app where you can quickly toggle pop-ups on or off.
Disabling Safari Pop-ups
If a pop-up is required for a page to function, you'll need to disable Safari's pop-up blocker, which will enable pop-ups for every page, not just the one you're visiting. However, the iPad conveniently places the controls in the Settings app, so you can quickly disable the pop-up again when you're through with the page. Tap "Safari" in the Settings app and slide the "Block Pop-ups" option to the left to disable the blocker. You'll need to reload the page before the pop-ups appear.
Pros and Cons of Disabling Pop-ups
Pop-ups can offer conveniences online, but they can also annoying, depending on the sites you traverse and your personal tolerances. Pop-ups helpfully allow secondary windows to display forms, information and photos without forcing you to leave the initial page, but pop-ups have a dark side as well, particularly in the hands of unscrupulous webmasters. If you're lucky, you're simply presented with an ad every now and then, but if you're unlucky, you're barraged with numerous pop-ups that then spawn additional windows in an endless cycle. Because the possibility of abuse is so high, it is best to keep the pop-up blocker disabled and only enable it when you need it for a specific, trusted website.