Online Advertising Sizes: Best Display Banners

The following online advertising sizes offer insights for both website publishers and website advertisers.

What is a 728 x 90 Leaderboard?

A 728 x 90 leaderboard is a horizontal online ad size that commonly appears at the top of pages on websites. It sometimes appears in the middle of articles if they are wide enough to accommodate the ad. It also may appear in the middle of index pages.

Publishers use the 728 x 90 at the top of pages because it is an efficient use of space and offers great visibility for advertisers. Site visitors don’t have to scroll to see the content underneath. Because of its high visibility, it often has high clickthrough rates.

Advertisers like the leaderboard for the visibility and click rates. But because of its strong horizontal presentation, it creates some challenges in how best to use the space for graphics, branding and responsiveness.

What is a 970 x 250 Billboard?

The 970 x 250 billboard is a leaderboard on steroids. This huge banner also usually appears at the top of pages because of its strong horizontal orientation. Its aggressive width and height means it rarely appears in any other ad position on the website. It has exceptional visibility.

Publishers like the 970 x 250 because its large size means they can charge a higher RPM (revenue per thousand impressions). Site visitors have to scroll more to see content underneath.

Advertisers are willing to pay a higher rate because the large size gives them more space for branding and because it usually has a higher click rate than the 728 x 90.

What is a 300 x 250 MPU?

The 300 x 250 MPU or Mid Page Unit is a popular online advertising size at the top of website sidebars. It usually appears under the 728 x 90 or 970 x 250 banners across the top of the page. It has high visibility if it appears under the narrow 728 x 90 and low visibility under the much deeper 970 x 250.

The 300 x 250 has one other advantage. It’s an excellent ad size to appear at the top of mobile pages, where it has a high clickthrough rate. But MPUs usually have a lower click rate and CPM when they appear on desktop sites in sidebars than at the top of mobile pages. Still, it usually has a high enough click rate to justify using the space.

Advertisers like 300 x 250s because their smaller size allows them to pay lower CPMs. The rectangle size also gives them more options with graphics than the much narrower 728 x 90.

What is a 300 x 600 HPU?

The 300 x 600 HPU or Half Page Unit is the second largest ad size after the 970 x 250 Billboard. It’s a common size in sidebars like the Mid Page Unit but has plenty of extra space for advertisers to display dominant, eye-catching graphics and text.

Publishers like the 300 x 600 because its large size allows them to charge a higher CPM than the 300 x 250. It also allows them to use sidebar space more effectively. But because of the sidebar location, which has lower visibility than the main content area, the HPU doesn’t command click rates as high as the top-of-page Billboard.

Another reason for the lower click rate is the ad’s depth. Website visitors have to scroll to see most if not all of the ad.

Despite the lower visibility, advertisers can use the HPU as a chance to display graphics and text in a different configuration.

Other Online Ad Sizes

Two online advertising sizes appear occasionally on websites but not as often as the above four. They are the 970 x 90 Super Leaderboard at the top of pages and the 160 x 600 Skyscraper in sidebars.

Other mobile sizes that are less popular include the 300 x 50 banner and 320 x 100 large mobile banner.