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.
Other research shows that exact-match domains that are deemed to be relevant, valuable, and high-quality can see a ranking boost because of it. However, if you already have an established website, you don’t need to go looking for an exact-match domain for your business; focus on a URL that reflects your business and optimize the heck out of it instead!
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.