But yes. You can put it anywhere on those pages.
Both of you are exactly 50% correct.
The Advanced text ad can be placed anywhere on every publically viewable page.
The Corporate banner ad must be visible without scrolling down on every publically viewable page.
Corporate's the fun one in that depending on screen res, you might have to scroll down. For safetys sake, assume the reviewer is going to be on 800x600 - if it's viewable without scrolling down on that, it'll be viewable without scrolling down on everything bigger too (and I highly doubt anyone's still on 640x480).