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If your adserver can adjust the creative size to the ad placement size, you can use resizable creative settings. You can use this feature in cases when, for example, a publisher has several different available formats – 336x280, 320x480, 300x600. You have to upload 3 creatives for each of those size to your adserver, and then you can upload single tag to cover all the mentioned sizes. Just set up Minimum and Maximum Width and Height and bid for all available sizes within the specified range.
List of adservers which are tested with GetIntent's resizable creatives feature
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