If ANYONE can see a page on your site, it's considered publicy visible. To clarify:
Corporate ads: Banner ad MUST be completely visible without scrolling
*Advanced ads: Text ad MUST be visible, but may be placed anywhere on the page
*Static ads: No ads necessary.
For the Corporate and Advanced package, each respective ad must be on every one of your publicly viewable page.
*If you display want to display the next packages' up ads instead, you may do so. For example, if you have Advanced and you want to display the Corporate ad, you may do so. However, you may NOT display Advanced ads if you have the Corporate plan. Hope this clarifies everything.