The Ad Formats & Specs page on our website has examples of the ad sizes we accept.
All sites on the MessageSpace network accept IAB web-standard ad sizes:
728×90 Leaderboards, 300×250 Medium Rectangles, and expandable units.
Some of our sites offer additional ad size capabilities, including 300×600 Half Page / Tall Rectangles, Background (Skin) Takeover Wraps, 970x250 Billboards, 160x600 Wide Skyscrapers and 125×125 Square Buttons.
All MessageSpace sites accept rich-media creatives (jpg, gif, animated gif, png, HTML5), and third-party ad tags from providers including but not limited to Atlas, DoubleClick, Eyewonder, PointRoll, RightMedia, and TangoZebra.
Our checklist for supplying creative files and assets will help if you're looking for information on how to deliver raw creative files. Visit our HTML5 creative specifications page to ensure your HTML5 ads are built to be compatible with the MessageSpace adserver.