Does anyone know why a leaderboard/banner ad is the exact size it is? I first thought about when the average screen was 800px wide: (800-728)/2 = 36 Nope. 728/90 = 8.09 I've got nothing.
Average screen (was) 800px wide, you'll also have to take into account the scrollbar, the UI for the web browser, possibly dialup banner ads on the top/bottom/right/left of the screen, AIM5 and older versions used to dock alwaysontop to the sides, etc. I honestly have no clue, just throwing that out there.