Running display ads (static banners or more complex Flash / video / interactive pieces) is much more
difficult than it should be, in part because different publications can have vastly different
standards (I can remember one time doing three different
versions each of four online ads, one set for the NY Times site, one set for Washington Post properties and one at
standard 468 × 60 banner size for National Journal) and in part because ads can't be ordered from a single central broker (a situation that AOL's Advertising.com for one is trying to change).