There are a variety of banner ad sizes that are popular among advertisers and publishers. The most common, and perhaps most effective, banner ad sizes are the Medium Rectangle (300×250), theLeaderboard (728×90), and the Wide Skyscraper (160×600). Each of these banner ad sizes has its own strengths and weaknesses, and it is important to select the right size for your campaign goals.
The Medium Rectangle is the most popular banner ad size on the web. It is small enough to not be intrusive, but large enough to garner attention and convey a message. This banner ad size is also very effective on mobile devices.
The Leaderboard is a larger banner ad size that is designed for desktop viewing. This size is less effective on mobile devices, but can be very effective when placed above the fold on a website.
The Wide Skyscraper is the largest of the three common banner ad sizes. This size is less effective on mobile devices and can be intrusive if placed above the fold on a website. However, this size can be very effective when placed below the fold on a website or in the middle of an article.