What are the file size limits of a banner ad?

The file size of a banner ad is measured in Kilobytes. Publishers set limits on the file size they allow for each physical size. For example, a 468x60 GIF animated banner ad can be 15K on Yahoo. Keeping file size down on a banner ad is advantageous to you because your banner ad will load faster if its file size is smaller. When ordering a banner ad, make sure you know what your file size limitations are, as this is essential when designing the banner ad.