If you are using Responsive Web Design, use meta name="viewport" tag to tell the browser how to adjust the content. If you use Dynamic Serving, use the Vary HTTP header to signal your changes depending on the user-agent. If you are using separate URLs, signal the relationship between two URLs by tag with rel="canonical" and rel="alternate" elements.
With the explosion of digital media, people began to engage with each other – and the companies they did business with – in new ways. The relevance of traditional print and broadcast channels declined, completely changing the consumer-corporation dynamic. Digital channels opened doors for consumers. No longer passive participants in a one-sided marketing conversation, consumers became empowered authors, publishers and critics. The digital landscape is participatory, an area where consumers exchange ideas. Marketers no longer drive the discussion. Everyday consumers are now the style makers and trendsetters.
Digital marketing is defined by the use of numerous digital tactics and channels to connect with customers where they spend much of their time: online. From the website itself to a business's online branding assets -- digital advertising, email marketing, online brochures, and beyond -- there's a spectrum of tactics that fall under the umbrella of "digital marketing."