Ads can be jpg, gif for flash format suitable for web display.

The maximum size for each type is listed below:

Web site Banner ads
250 px. x 60 px.

Web site Small column display ads
250 px. x 125 px.

Web site Standard column display ads
250 px. x 250 px.

Web site Skyscraper column display ads
250 px. x 600 px.

Travel Banner
440 px. x 100 px.

Travel Display
200 px. x 200 px.

eNewsletter Banner ads
400 px. x 100 px.