Expertise and authoritativeness of a site increases its quality. Be sure that content on your site is created or edited by people with expertise in the topic. For example, providing expert or experienced sources can help users understand articles’ expertise. Representing well-established consensus in pages on scientific topics is a good practice if such consensus exists. Internet Marketing
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. Internet Marketing
Not every single ad will appear on every single search. This is because the ad auction takes a variety of factors into account when determining the placement of ads on the SERP, and because not every keyword has sufficient commercial intent to justify displaying ads next to results. However, the two main factors that Google evaluates as part of the ad auction process are your maximum bid and the Quality Score of your ads. Search Engine Optimization (SEO)