A web banner or banner ad is a form of advertising on the World Wide Web delivered by an ad server. This form of online advertising 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.
If you are a local business you would usually need banners to announce sales, events your business is holding, new products or services or general announcements.
Many businesses would ask for seasonal banners to be designed so that they can attract customers with offers around Easter,Christmas or NY.
If you are an online retailer and your whole business is entirely online you would definitely need regular updates on your web banners. There is so much competition out there and you can not afford to fall behind if you want your products to be selling and your brand to have current appearance.
You would need new banners for each collection coming in to your website, sometimes even new product will need a new banner and a spotlight. You need banners to attract customers with codes for offers, free delivery announcements, seasonal greetings and many many more.