I think a lot of page admin’s on Facebook look over the constraints and properties of their cover photos all too often. Cover photos dimensions should be: 851 pixels wide and 315 pixels tall for desktop, 640 pixels wide by 360 pixels tall for mobile. The mobile box is 555 pixels wide (essentially chopping off the outer edges of the original desktop version). Why does this matter so much? Well for one, first impressions are everything, if you have text copy or an image that is clearly and unintentionally cut out, potential customers take notice. There are a lot of statistics that correlate design with sales; the better the design of the page, the higher the sales, page views, followers etc… Also, Facebook has changed these properties in the past so it’s important to keep a watchful eye of changes and act accordingly. A good cover photo results in better page performance.