Relevancy is the first qualifier of a quality link opportunity. The next qualifying factor is the authority of the opportunity. Since Google doesn’t update PageRank (PR) anymore, you must rely on third party metrics. I recommend you use Domain Authority (DA) from Open Site Explorer, Domain Rate (DR) from Ahrefs, or Trust Flow from Majestic to determine the quality of your link opportunities. You should use all three tools if you can.
You may not want certain pages of your site crawled because they might not be useful to users if found in a search engine's search results. If you do want to prevent search engines from crawling your pages, Google Search Console has a friendly robots.txt generator to help you create this file. Note that if your site uses subdomains and you wish to have certain pages not crawled on a particular subdomain, you'll have to create a separate robots.txt file for that subdomain. For more information on robots.txt, we suggest this Webmaster Help Center guide on using robots.txt files13.
The goal of SEO is to get a web page high search engine ranking. The better a web page's search engine optimization, the higher a ranking it will achieve in search result listings. (Note that SEO is not the only factor that determines search engine page ranks.) This is especially critical because most people who use search engines only look at the first page or two of the search results, so for a page to get high traffic from a search engine, it has to be listed on those first two pages, and the higher the rank, the closer a page is to the number one listing, the better.
SEO may generate an adequate return on investment. However, search engines are not paid for organic search traffic, their algorithms change, and there are no guarantees of continued referrals. Due to this lack of guarantees and certainty, a business that relies heavily on search engine traffic can suffer major losses if the search engines stop sending visitors. Search engines can change their algorithms, impacting a website's placement, possibly resulting in a serious loss of traffic. According to Google's CEO, Eric Schmidt, in 2010, Google made over 500 algorithm changes – almost 1.5 per day. It is considered a wise business practice for website operators to liberate themselves from dependence on search engine traffic. In addition to accessibility in terms of web crawlers (addressed above), user web accessibility has become increasingly important for SEO.
Moving into 2016, your website needs to be mobile-ready. There are three types of accepted options for a mobile site in Google’s eyes: responsive design, being set up on a mobile subdomain or use dynamic serving. Google also now ranks websites higher that apply SEO for their apps. So if you have an app, make sure you are taking the time to implement application SEO.
Schema.org is a type of markup that you can put in the code of your website. Using schema.org, you can tell Google which picture on your site is your logo, where your reviews are, where your videos are, what type of company you are, where you are located and much more. Google has hinted over the last year that schema.org will help your website rank better in Google search. Recently, Google’s John Mueller, said in a Google Hangout on Sept. 11 (at the 21:40 minute mark) that “over time, I think it [structured markup] is something that might go into the rankings as well.”
Every website should have a content strategy focused around your top keywords. When you create content such as blog posts, videos, whitepapers, research reports and webinars, it gives people something to link to. In addition, the content you create can rank by itself in the search engines. For example, if you write a blog post on “How to Pick an SEO Company,” there is a possibility it will rank for some of the keywords you use in the title and in the body post, especially if the post gets linked to from other websites or shared a lot on social media. It also helps if your website as a whole already has significant high-quality links.