Domain authority is an important ranking phenomenon in Google. Nobody knows exactly how Google calculates, ranks and rates the popularity, reputation, intent or trust of a website, outside of Google, but when I write about domain authority I am generally thinking of sites that are popular, reputable and trusted – all of which can be faked, of course.
TASK – If running a blog, first, clean it up. To avoid creating pages that might be considered thin content in 6 months, consider planning a wider content strategy. If you publish 30 ‘thinner’ pages about various aspects of a topic, you can then fold all this together in a single topic page centred page helping a user to understand something related to what you sell.
What about other search engines that use them? Hang on while I submit my site to those 75,000 engines first [sarcasm!]. Yes, ten years ago early search engines liked looking at your meta-keywords. I’ve seen OPs in forums ponder which is the best way to write these tags – with commas, with spaces, limiting to how many characters. Forget about meta-keyword tags – they are a pointless waste of time and bandwidth.

QUOTE: “To summarize, a lack of helpful SC may be a reason for a Low quality rating, depending on the purpose of the page and the type of website. We have different standards for small websites which exist to serve their communities versus large websites with a large volume of webpages and content. For some types of “webpages,” such as PDFs and JPEG files, we expect no SC at all.” Google Search Quality Evaluator Guidelines 2017
Ever since its April 2015 update, Google is now taking the user's mobile experience into consideration in its search results. This means that when a user is doing a search on a mobile device, Google's search results will favor websites that are mobile friendly over the ones that aren't. If you want to capture that mobile search audience, you will need to have a mobile version of your website in addition to your desktop version.
Keyword analysis. From nomination, further identify a targeted list of key­words and phrases. Review competitive lists and other pertinent industry sources. Use your preliminary list to determine an indicative number of recent search engine queries and how many websites are competing for each key­word. Prioritize keywords and phrases, plurals, singulars and misspellings. (If search users commonly misspell a keyword, you should identify and use it). Please note that Google will try to correct the term when searching, so use this with care.
QUOTE: “So sites that don’t have much content “above-the-fold” can be affected by this change. If you click on a website and the part of the website you see first either doesn’t have a lot of visible content above-the-fold or dedicates a large fraction of the site’s initial screen real estate to ads, that’s not a very good user experience.” Google 2012
Websites that have extremely negative or malicious reputations. Also use the Lowest rating for violations of the Google Webmaster Quality Guidelines. Finally, Lowest+ may be used both for pages with many low-quality characteristics and for pages whose lack of a single Page Quality characteristic makes you question the true purpose of the page. Important: Negative reputation is sufficient reason to give a page a Low quality rating. Evidence of truly malicious or fraudulent behavior warrants the Lowest rating.
Ever heard of Maslow's hierarchy of needs? It's a theory of psychology that prioritizes the most fundamental human needs (like air, water, and physical safety) over more advanced needs (like esteem and social belonging). The theory is that you can't achieve the needs at the top without ensuring the more fundamental needs are met first. Love doesn't matter if you don't have food.