1) Backlinks remain an extremely important Google ranking factor. We found the number of domains linking to a page correlated with rankings more than any other factor. On the other hand, you may have heard that getting backlinks from the same domain has diminishing returns. In other words, it’s better to get 10 links from 10 different sites than 10 links from the same domain.
Pages with the highest number total backlinks tended to rank best in Google.
Even though Google continues to add diversity to its algorithm, it appears that backlinks remain a critical ranking signal. But it’s typically better to get a single link from an authoritative page than 100 links from 100 low-quality pages.
2) Domain authority strongly correlates with higher rankings. So it's important to get backlinks with high authority. You can test domain authority here: http://smallseotools.com/domain-authority-checker/ TripAdvisor has a domain authority of 94,75 on 100, so having a business listing on TripAdvisor dramatically boost ranking on search engines:
3) Content rated as “topically relevant” significantly outperform content that don't cover a topic in-depth.
In the early days of SEO, Google would determine a page’s topic by looking strictly at the keywords that appeared on the page.
If the keyword appeared on the page X number of times, Google would determine that the page was about that keyword. Today, thanks largely to the Hummingbird Algorithm, Google now understands the topic of every page.
Google should prefer content that covers a single topic in-depth.
Comprehensive content significantly outperform shallow content.
That means that a website page that talks with pertinence about "LUXURY HOTEL" without EVER using the keyword LUXURY HOTEL will rank higher than a website page using the traditional metrics (LUXURY HOTEL keyword in the title tag and the H1 tag) but content that is not totally pertinent, due to the fact the content on the page has a very low Topical Authority score. Writing comprehensive, in-depth content can help you rank higher in Google and this has nothing to do with keywords.
4) Longer content tends to rank higher in Google’s search results. The average Google first page result contains 1,890 words. Longer content boosts your page’s topical relevancy, which gives Google a deeper understanding of your content’s topic.
5) HTTPS had a reasonably strong correlation with first page Google rankings.
Last year Google called on webmasters to switch their sites over to secure HTTPS. They even called HTTPS a “ranking signal“.
Although not a super-strong correlation, HTTPS correlates with higher rankings on Google’s first page.
Anyway, because the association between HTTPS and ranking isn't especially strong — and the fact that switching to HTTPS is a resource-intensive project — it's not recommend switching to HTTPS solely for SEO.
6) Content with at least one image significantly outperformed content without any images. Industry studies have found that image-rich pages tend to generate more total viewsand social shares. This suggests that including lots of images in your content can boost shares, which should therefore improve Google rankings. On the other hand, when you look at the link between the total number of images and rankings, there's no correlation.
Using a single image is clearly better than zero images. Including lots of images doesn’t seem to have an impact on search engine rankings.
7) There's a very small relationship between title tag keyword optimization and ranking. This correlation may reflect Google’s move to Semantic Search. Google doesn’t need to see the exact keyword in your title tag to understand your page’s topic. For example: if you analyze top 6 results for the keyword “list building” 3 of the top 6 results (including the #1 result) don’t contain the exact keyword “list building” in their title tag.
Including your target keyword in your title tag may help with rankings for that keyword. However, because of Semantic Search, the impact doesn’t appear to be nearly as great as it once was.
8) Site speed matters. Pages on fast-loading sites rank significantly higher than pages on slow-loading sites. Since 2010, Google has used site speed as an official ranking signal.
9) Low bounce rate is associated with higher Google rankings.
Websites with low average bounce rates are strongly correlated with higher rankings.
Google may use bounce rate as a ranking signal (although they have previously denied it). Or it may be the fact that high-quality content keeps people more engaged. Therefore lower bounce rate is a byproduct of high-quality content, which Google does measure.
10) Shorter URLs tend to Rank Better than Long URLs
According to Google’s Matt Cutts, after 5 words in your URL, Google algorithms typically will just weight those words less and just not give you as much credit.
Second, a long URL tends to point to a page that’s several clicks from the homepage. That usually means that there’s less authority flowing to that page. Less authority means lower rankings.