The 728×90 is ideal for top-of-page Placements

The 728×90 ad unit, also known as the leaderboard, is typically placed at the top of a website either above the content or within the header itself. Because of it’s above-the-fold placement on many websites, the 728×90 performs extremely well for advertisers. Across Gourmet Ads, the 728×90 ad unit is popular on large recipe and food sites and is often run near a 300×250 for maximum brand exposure. For advertisers, the 728×90 is considered a high-performance ad unit, and is used in nearly every campaign run on Gourmet Ads publisher sites.