Digital marketing involves search engine optimization (SEO) and increasing website traffic. SEO is the practice of optimizing a website to rank higher in search engine results pages through on-page techniques like optimizing website content, and off-page techniques like earning backlinks. Website traffic can come from organic sources like direct visits or social media, or inorganic sources like paid advertising. Other digital marketing techniques include directory submissions to build backlinks, classified advertising to promote products and services, and social bookmarking to share and remember webpage links.