This post tries to identify some of the most profitable Banner ad sizes in the industry. If you are in a dilemna as to what banner ad size to display on your blog / website, then you are invited to read on. What is a Banner ad? According to wikipedia, A banner ad is a form of online advertising which "entails embedding an advertisement into a web page. It is intended to attract traffic to a website by linking to the website of the advertiser. The advertisement is constructed from an image (GIF, JPEG, PNG), JavaScript program or multimedia object employing technologies such as Java, Shockwave or Flash, often employing animation, sound, or video to maximize presence." What are the standard Banner ad sizes? The standard banner ad sizes in the industry are:- Rectangle Medium Rectangle - 300 x 250 px Square - 250 x 250 px Pop Under - 720 x 300 px Vertical Rectangle - 240 x 400 px Banners & Buttons Leaderboard - 728 x 90 px Full Banner - 468 x 60 px Half Banner - 234 x