Similar to and works in the same way as a banner ad – see banner ad. The main difference is that it is taller – often reaching 600 pixels in height and 120 pixels in width. Because of the height sidebar ads are more difficult to scroll off screen than banner ads and so stay visual for longer – increasing the chance of the user seeing and taking note of the ad. Sidebar ads, therefore, have greater branding power and a higher click through rate, sometimes two to three times higher than a banner ad.