We recommend having a variety of banners sizes available for your Offer(s). This will make it easier for Publishers to promote your Offers and generate better results.
Banners are measured by the width x height in pixels. The most common ad sizes are:
Desktop Offers
250 x 250 – Square
200 x 200 – Small Square
468 x 60 – Banner
728 x 90 – Leaderboard
300 x 250 – Inline Rectangle
336 x 280 – Large Rectangle
120 x 600 – Skyscraper
160 x 600 – Wide Skyscraper
300 x 600 – Half-Page Ad
600 x 315 – Shared Post Image
970 x 90 – Large Leaderboard
970 x 250 – Billboard
Mobile Offers
300 x 250 – Medium Rectangle
320 x 50 – Mobile Leaderboard
300 x 50 – Mobile banner
We recommend keeping the file size under 150 KB and in the following formats: jpeg, swf, png, or gif.
You can always find more information about sizes on iab.com