More than three billion people in the world are active on the Internet. Over the years, the Internet has continually gained more and more users, jumping from 738 million in 2000 all the way to 3.2 billion in 2015.[9] Roughly 81% of the current population in the United States has some type of social media profile that they engage with frequently.[10] Mobile phone usage is beneficial for social media marketing because of their web browsing capabilities which allow individuals immediate access to social networking sites. Mobile phones have altered the path-to-purchase process by allowing consumers to easily obtain pricing and product information in real time[11]. They have also allowed companies to constantly remind and update their followers. Many companies are now putting QR (Quick Response) codes along with products for individuals to access the company website or online services with their smart phones. Retailers use QR codes to facilitate consumer interaction with brands by linking the code to brand websites, promotions, product information, and any other mobile-enabled content. In addition, Real-time bidding use in the mobile advertising industry is high and rising due to its value for on-the-go web browsing. In 2012, Nexage, a provider of real time bidding in mobile advertising reported a 37% increase in revenue each month. Adfonic, another mobile advertisement publishing platform, reported an increase of 22 billion ad requests that same year.[12]

Users will occasionally come to a page that doesn't exist on your site, either by following a broken link or typing in the wrong URL. Having a custom 404 page30 that kindly guides users back to a working page on your site can greatly improve a user's experience. Your 404 page should probably have a link back to your root page and could also provide links to popular or related content on your site. You can use Google Search Console to find the sources of URLs causing "not found" errors31.
In addition to giving you insight into the search volume and competition level of keywords, most keyword research tools will also give you detailed information about the average or current estimated CPC for particular keywords are. This is particularly important for businesses with smaller ad budgets and this feature allows you to predict whether certain keywords will be truly beneficial to your ad campaigns or if they’ll cost too much.
When Googlebot crawls a page, it should see the page the same way an average user does15. For optimal rendering and indexing, always allow Googlebot access to the JavaScript, CSS, and image files used by your website. If your site's robots.txt file disallows crawling of these assets, it directly harms how well our algorithms render and index your content. This can result in suboptimal rankings.
Webmasters and content providers began optimizing websites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters only needed to submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed.[5] The process involves a search engine spider downloading a page and storing it on the search engine's own server. A second program, known as an indexer, extracts information about the page, such as the words it contains, where they are located, and any weight for specific words, as well as all links the page contains. All of this information is then placed into a scheduler for crawling at a later date.