The Periodic Table Of SEO Success Factors: 2015 Edition Now Released

Three new elements join the table: Vertical Search, Direct Answers & HTTPS. Mobile & Structured Data among factors that get weight increases.

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Periodic Table Of SEO Success Factors 2015

The latest version of Search Engine Land’s Periodic Table Of SEO Success Factors is now out. This is the third edition since we first launched our search engine optimization framework in 2011. Below, a rundown of what’s new and changed, as well as a reintroduction to the table.

The Table’s Goal & Philosophy

Our goal with the Periodic Table Of SEO is to help publishers focus on the fundamentals needed to achieve success with search engine optimization. This means it’s not about trying to list all 200 Google ranking factors or detail Google’s 10,000 subfactors. It’s not about trying to advise if keywords you want to rank for should go at the beginning of an HTML title tag or the end. It’s not about whether or not Facebook Likes are counted for ranking boosts.

Instead, the table is designed to broadly guide those new to or experienced with SEO into general areas of importance. Title tags are generally important. Think about making sure they’re descriptive. Social sharing is often generally seen as good for SEO. Aim for social shares, without worrying about the specific network.

If you want to understand more about the philosophy of the table, read our posts from when the table debuted in 2011 and when it was updated in 2013.

What The SEO Table Covers

There are two major classes of factors:

  • On-The-Page: factors that are largely within the control of publishers
  • Off-The-Page: factors are influenced often by others or not directly tied to a publisher’s site

Within these two classes are seven categories of factors, which are:

  • Content – factors relating to the content and quality of your material
  • Architecturefactors about your overall site functionality
  • HTML – factors specific to web pages
  • Trust – factors related to how trustworthy & authoritative a site seems to be
  • Links – factors related to how links impact rankings
  • Personal – factors about how personalized search results influence rankings
  • Social – factors on how social recommendations impact rankings

Overall, there are 37 individual factors, which range from making use of descriptive HTML title tags to whether a site has success with visitor engagement. Here’s a close-up of the table, focusing on just the factors:

Periodic Table Of SEO Success Factors

How To Use The Table

Each factor has a two letter symbol. The first letter represents the category the factor is part of, such as A for Architecture. The second letter represents the element itself, such as m for Mobile, giving Am its symbol.

Each factor also has a weight. This is a relative guide to how important it is to focus on a particular factor versus others and overall. Those with a +3 are most important, with +2 and +1 factors of lesser importance.

It’s also important to understand that the factors work together. No one factor will guarantee success. But several factors working together, even if they are minor ones, can increase the odds in your favor.

Violations are negative factors, spam activities that can harm your visibility. Don’t do these things! Violations, unlike the other elements, all begin with V regardless of what category they are in, so that they can more easily be identified as violations. With the weighting, factors marked -3 are considered worse than -2 and -1.

Our Search Engine Land’s Guide To SEO has been updated to reflect all the changes to the table, and it goes into more depth about each factor. Be sure to check it out!

What’s Changed?

As with last year, the Search Engine Land editors brainstormed new elements that should be included, pondered ones that should perhaps be dropped or lowered in weight as well as those that deserved a boost.

We also ran a survey asking people to give their own opinion of how existing elements should be weighted. For new elements and one we were considering deleting (Identity/Authorship), we also allowed for weighting plus comments. We received nearly 400 responses in all — thanks to all you helped!

For 2015, the table has gained three new elements and four had weight increases. The summary is below. If you don’t care about the changes, then please scroll past to our related resources, including how to get the table for yourself.

New Factors

Cv: Vertical Search — As the days of “10 blue links” are long-gone, which rich search results often pulling in image, news, video and local results from vertical search engines, we felt the table should recognize that vertical search can be an important success factor. Those surveyed seemed to agree, rating this a 1.7 weight, on average. We’ve settled on making it a +2, for its debut on the table.

Ca: Direct Answers — It’s common that search engines these days show direct answers that are taken off web pages. But is it a success for a page to be scraped for its content in this way, if the answer means there’s no need to click to the page at all? We decided yes. First, being picked to provide a direct answer seems a sign of trust, which may help a site for other types of queries. Second, while there’s concern, there’s also some evidence that being selected as a direct answer can indeed send traffic. The survey put this at a 1.8 weight, but the Search Engine Land editors felt having it debut at +1 was more appropriate.

Ah: HTTPS — As Google explicitly added having an HTTPS secure site as a ranking boost last year, it was a no-brainer to add it to the part. The survey gave this a 1.5 average weight. Given that even Google says it’s fairly minor, we felt making it +1 was appropriate.

Changed Factors

Am: Mobile — Previously +1, the survey averaged at 2.6. We thought rounding to +3 would give this too much weight. But it did deserve to go to +2 given that both Google and Bing are now looking at mobile friendliness as a ranking factor. FYI, we also considered having a separate Aa factor for app indexing. That rated 1.5 on the survey. We decided for this edition to include app indexing / linking as part of mobile overall.

Hs: Structured Data — Previously weighted +1, the survey average was 2. We also agreed that it has grown in importance, so it was increased to +2.

Th: History — Previously +1. The survey average was 2. We agreed with that, so it has been increased to +2.

Te: Engagement — Previously within Content, this now moves to the Trust area. Stays at 2, in line with the survey having it at 2.3.

Vs: Stuffing — Previously it was -1. The survey average was -2.6. We felt rounding up to -3 was too high, but we have taken it to -2.

Vp: Spam — Previously it was -1. Survey average was -2.6. In this case, we felt agreed with rounding up to -3.

Va: Ads — Previously within Content, this now moves to the Trust area. The survey had it at 2.1, but we’ve kept it at -1 because relatively speaking, we don’t think it’s that big an issue for most sites.

Not Changed But Notable

As you can see above, we didn’t always go with exactly what the survey suggested. Ultimately, we try to be a bit more cautious than what the survey suggests. Here are some notable diversions from the survey:

As: Speed — The survey put this at 2.4, but when even Google says it’s a fairly minor factor, leaving it at +1 seemed appropriate.

Au: URLs — The survey had this at 2.2, but we felt keeping it a +1 was fair.

Hh: Headers — The survey had this at 2.2, but we felt that was too much weight for what’s a relatively minor factor. We kept it at +1.

Ti: Identity — With the death of formal Google Authorship, we seriously debated whether this should be dropped from the table. But the survey ranked it 1.6, a pretty strong showing for a factor that seemed diminished. Ultimately, we think identity will remain important even if how it is determined changes. So, this factor survived, staying on the chart as +1, as before.

Ln: Numbers — The survey had this at 1.9. Rounding that to give this a weight of +2 felt overkill from the +1 that it was at, especially at a time when Google has cracked down on people who simply get a lot of links rather than quality ones. We felt keeping it at +1 was more appropriate.

Pc: Country — The survey ranked this as 2.2, but we felt country-specific results can be so dramatic that +3 was appropriate.

Pl: Locality — Like Country, Locality/City was 2.2 on the survey but we have it at +3, as before. It feels right to keep it this strong. It’s a big factor.

Ph: History — The survey had this at 1.8, lower than the existing +3. We considered dropping it to +2 but decided ultimately to keep it at +3, because we think search history is a bigger factor than some are giving it credit for.

Ps: Social — With the pullback on Google+, there was an argument for dropping this from +2 to +1. But the survey put it at 1.6, which is +2 rounded. We decided to hold with the current weight.

Ss: Shares — While the survey put this at 1.7, which would round to +2, we didn’t think a factor that’s about the number of social shares versus the reputation/authority of those warranted this. We kept it at +1.

Vh: Hidden — Oops! We forgot to ask about this on the survey, but we thought keeping it at -1 was fine.

Vp: Paid — The survey only gave it 2.2. but we’ve kept it at -3 because those hit by paid link penalties have difficult recovery, if they ever do.

Vp: Piracy — The survey put this at 2.5, which would round to -3. We agree, this is a severe penalty. But since most people aren’t pirating content or likely to get hit by many DMCAs, we felt keeping it at -1 was appropriate.


Getting the table updated for 2015 was a huge effort. Some thanks are in order:

First, thanks to Keri Morgret, who helped compile and analyze the survey results and has been busy updating the table’s associated SEO guide.

Next, thanks again to all those who participated in the survey!

As always, thanks to the Search Engine Land editors who participated in getting this edition of the guide updated, with a special call-out for our news editor Barry Schwartz, who has the pulse of SEO like no one else.

Thank you to David Chordigian of our Third Door Media tech department, for his assistance in getting the existing table updated.

Finally, big thanks again to the great folks at Column Five Media, who helped create the original table in 2011 and have continued to support it since through the updates.

Related Resources

The table can be viewed in a larger format on its home page, where you’ll also find options to download a PDF if you with to print it or codes to embed on your own site. Here’s the home page:

The table has an associated guide that explains more about the various factors, all freshly updated. You’ll find that here:

If you don’t know what SEO is or are new to it, don’t panic! Our overview page will help. It even has a movie!

We hope you enjoy the latest edition of the table. As always, Lq, Lt, Ln and Ss are deeply appreciated!

Contributing authors are invited to create content for Search Engine Land and are chosen for their expertise and contribution to the search community. Our contributors work under the oversight of the editorial staff and contributions are checked for quality and relevance to our readers. The opinions they express are their own.

About the author

Danny Sullivan
Danny Sullivan was a journalist and analyst who covered the digital and search marketing space from 1996 through 2017. He was also a cofounder of Third Door Media, which publishes Search Engine Land and MarTech, and produces the SMX: Search Marketing Expo and MarTech events. He retired from journalism and Third Door Media in June 2017. You can learn more about him on his personal site & blog He can also be found on Facebook and Twitter.

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