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.
NOTE, in 2020, the HTML title element you choose for your page, may not be what Google chooses to include in your SERP snippet. The search snippet title and description is very much QUERY & DEVICE dependent these days. Google often chooses what it thinks is the most relevant title for your search snippet, and it can use information from your page, or in links to that page, to create a very different SERP snippet title.
QUOTE: “If you have comments on your site, and you just let them run wild, you don’t moderate them, they’re filled with spammers or with people who are kind of just abusing each other for no good reason, then that’s something that might kind of pull down the overall quality of your website where users when they go to those pages might say, well, there’s some good content on top here, but this whole bottom part of the page, this is really trash. I don’t want to be involved with the website that actively encourages this kind of behavior or that actively promotes this kind of content. And that’s something where we might see that on a site level, as well.” John Mueller, Google 2016
The SEO starter guide describes much of what your SEO will do for you. Although you don't need to know this guide well yourself if you're hiring a professional to do the work for you, it is useful to be familiar with these techniques, so that you can be aware if an SEO wants to use a technique that is not recommended or, worse, strongly discouraged.