An important factor in ranking is review signals, which refers to the quality, quantity, velocity, and diversity of reviews you get from customers. This rank factor is intriguing as it has jumped up year-over-year in importance. Google reviews are the most important, followed by third-party reviews (Yelp, Facebook, and other sites). It’s also important to get your product/service mentioned in the review. There is even some suggestion that responses to reviews are a factor in rank.
This is a great list of SEO tips. One tip you can add to your broken links section is that there is a free tool called Xenu Link Sleuth. It will automatically crawl your website (or a competitor’s site) and find all the broken backlinks (and lots of other things). It’s very helpful if you have a large site or need to find broken links you aren’t aware of. (like images and .pdf files)
Google updates its search algorithm frequently. For example, on February 23rd, 2016, Google made significant changes to AdWords, removing right-column ads entirely and rolling out 4-ad top blocks on many commercial searches. While this was a paid search update, it had significant implications for CTR for both paid and organic results, especially on competitive keywords.
Organic search results are free and display below Google Ads and sometimes local results. Google uses a sophisticated algorithm to determine which sites rank highest for organic search results based on keyword usage, relevance, site design, and other factors. Generally, Google provides the highest quality, most relevant results based on the keyword(s) used by the searcher.