Advertisers have a wide variety of ways of presenting their promotional messages, including the ability to convey images, video, audio, and links. Unlike many offline ads, online ads also can be interactive. For example, some ads let users input queries or let users follow the advertiser on social media. Online ads can even incorporate games.
Search engine optimization is a key part of online marketing because search is one of the primary ways that users navigate the web. In 2014, over 2.5 trillion searches were conducted worldwide across search engines such as Google, Bing, Yahoo, Baidu, and Yandex. For most websites, traffic that comes from search engines (known as "natural" or "organic" traffic) accounts for a large portion of their total traffic.