According to Statistica, 76% of the U.S. population has at least one social networking profile and by 2020 the number of worldwide users of social media is expected to reach 2.95 billion (650 million of these from China alone). Of the social media platforms, Facebook is by far the most dominant - as of the end of the second quarter of 2018 Facebook had approximately 2.23 billion active users worldwide (Statistica). Mobile devices have become the dominant platform for Facebook usage - 68% of time spent on Facebook originates from mobile devices. Other popular social media platforms for marketing include WhatsApp, WeChat, Instagram, Twitter, LinkedIn, Pinterest, and YouTube.
The basics of GOOD SEO hasn’t changed for years – though effectiveness of particular elements has certainly narrowed or changed in type of usefulness – you should still be focusing on building a simple site using VERY simple SEO best practices – don’t sweat the small stuff, while all-the-time paying attention to the important stuff  – add plenty of unique PAGE TITLES and plenty of new ORIGINAL CONTENT. Understand how Google SEES your website. CRAWL it, like Google does, with (for example) Screaming Frog SEO spider, and fix malformed links or things that result in server errors (500), broken links (400+) and unnecessary redirects (300+). Each page you want in Google should serve a 200 OK header message.
SEM results show to a select target audience. SEO results do not. While successful SEO and SEM strategies are driven by a plan to connect with a select audience, you can only specify that target audience through SEM. Through SEM, you can (depending on the publisher) select what audiences you want to see the search results by assigning filters based on age, location, income, habits, and more. Through SEO, you cannot specifically choose who will see your search results.
Sometimes, Google turns up the dial on demands on ‘quality’, and if your site falls short, a website traffic crunch is assured. Some sites invite problems ignoring Google’s ‘rules’ and some sites inadvertently introduce technical problems to their site after the date of a major algorithm update and are then impacted negatively by later refreshes of the algorithm.
To get even more insight and data to help you make those decisions, sign up for a free trial of Alexa’s Advanced Plan. You’ll get access to tools that help you research competitor search and link building strategies, find keyword opportunities, review your site’s SEO, and learn about your target audience. These insights, paired with what you know about SEM and SEO, will help you uncover the best search marketing strategy for your unique brand and goals.
The reality in 2020 is that if Google classifies your duplicate content as THIN content, or MANIPULATIVE BOILER-PLATE or NEAR DUPLICATE ‘SPUN’ content, then you probably DO have a severe problem that violates Google’s website performance recommendations and this ‘violation’ will need ‘cleaned’ up – if – of course – you intend to rank high in Google.
QUOTE: “Fixing the problem depends on the issue you have. For example, if it’s a pop-up, you’ll need to remove all the pop-up ads from your site. But if the issue is high ad density on a page, you’ll need to reduce the number of ads. Once you fix the issues, you can submit your site for a re-review. We’ll look at a new sample of pages and may find ad experiences that were missed previously. We’ll email you when the results are in.” Google, 2017
Another illicit practice is to place "doorway" pages loaded with keywords on the client's site somewhere. The SEO promises this will make the page more relevant for more queries. This is inherently false since individual pages are rarely relevant for a wide range of keywords. More insidious, however, is that these doorway pages often contain hidden links to the SEO's other clients as well. Such doorway pages drain away the link popularity of a site and route it to the SEO and its other clients, which may include sites with unsavory or illegal content.