Ninthlink | 336 followers on LinkedIn. We create, promote, and grow your business online. Ninthlink is a leading, full service design, development and Internet marketing agency located in downtown San Diego, CA and consists of a talented mix of creatives, engineers, marketers, copywriters, strategists, and visionaries. Ninthlink designers are ready to listen to your business needs and create websites, applications, email campaigns, facebook pages, and more.