Google, being the largest search engine in the world, has a vast amount of data that allows it to determine what works best when it comes to online advertising. Display banners are an important aspect of online advertising and Google recommends using certain sizes for these banners. These sizes have been found to be effective in attracting clicks and conversions, but it is important to note that they are not a one-size-fits-all solution.

The recommended sizes for display banners by Google are as follows:

  1. 300 x 250 (Medium Rectangle): This size is commonly used in the sidebar of a webpage and can be effective in attracting clicks.
  2. 336 x 280 (Large Rectangle): This size is similar to the medium rectangle but is larger and can be placed in various locations on a webpage.
  3. 728 x 90 (Leaderboard): This size is commonly used at the top of a webpage and can be effective in attracting attention.
  4. 300 x 600 (Half Page): This size is larger than the medium and large rectangle and can be used to showcase more information.
  5. 320 x 100 (Large Mobile Banner): This size is specifically designed for mobile devices and can be effective in attracting clicks.

These sizes have been found to be effective in attracting clicks and conversions, but it is important to note that the effectiveness of a display banner depends on various factors such as the target audience, the message being conveyed, and the placement of the banner on the webpage. For example, a banner that is placed at the top of a webpage may be more effective than a banner that is placed in the sidebar.

It is recommended to test different sizes and variations of banners to see which ones perform best for your specific campaign. This is known as A/B testing and involves creating two or more versions of a banner and testing them against each other to see which one performs better. This can help you to optimize your campaigns and get the best possible results.

In addition to testing different sizes and variations of banners, it is also important to consider other factors such as the design of the banner, the message being conveyed, and the target audience. The design of the banner should be visually appealing and should convey the message effectively. The message should be clear and concise and should be tailored to the target audience.

Google recommends using certain sizes for display banners, but it is important to note that the effectiveness of a display banner depends on various factors. It is recommended to test different sizes and variations of banners to see which ones perform best for your specific campaign. By doing so, you can optimise your campaigns and get the best possible results.