SEO in 2015: What Happened When? / Business Intelligence / Last Modified: February 22, 2017

Now that we've made it to the end of 2015, it's time to reflect on the many SEO changes that happened this year.

One of the biggest responsibilities SEOs have on their plate is keeping up with the ever-changing search environment. 

A proactive way to stay sharp is to reflect on the past successes and failures of yourself and others.

As we approach 2016, it’s time to take a look at all the major events and changes that happened in the industry this year.

Related Article: 6 Toxic SEO Habits You Should Stop Today

Algorithm Updates and Refreshes

Google updates or refreshes their algorithm around 500 times a year, but some have more impact than others. Below is an outline of the major updates from 2015:

May  Almost halfway through 2015, there were murmurs of an algorithm update. While news sources were weary of reporting an official update as Google refused to confirm or deny an update occurred, the rumored updates were dubbed “Phantom Update.” Search Engine Land(SEL) confirmed later in the month the update was official and re-named it "Quality Update." There wasn't much to report in terms of what Google targeted in this update other than putting more focus on quality content.

July – During the third week of July, Google confirmed they were rolling out the 30th Panda refresh, Panda 4.2. According to Search Metrics, this refresh affected 2-3 percent of all searches on Google (approximately 36 million monthly). The update emphasized sites with high-quality content and de-emphasized aggregated or poor quality content.

October – Panda 4.2 continued to roll out into October. SEL mentioned they saw two different ranking changes in the month, some of which were due to Panda. Though unconfirmed by Google, SEL identified:

  • October 14-15: ongoing Panda rollout
  • October 20-21: a suspected mix of Panda and potentially some other ranking adjustment Google made

October also brought a major announcement from Google—the use of artificial intelligence in their core algorithm named RankBrain. Greg Corrado, a senior research scientist with google told Bloomberg:  RankBrain “… uses artificial intelligence to embed vast amounts of written language into mathematical entities – called vectors – that the computer can understand.  If RankBrain sees a word or phrase it isn’t familiar with, the machine can make a guess as to what words or phrases might have a similar meaning and filter the result accordingly, making it more effective at handling never-before-seen search queries.”

November – Google updated their Quality Rating Guidelines and publicly announced changes for the first time since 2013. You can find the entire guidelines here, but there aren’t too many surprises to be found.

TL;DR Algorithm Update and Refreshes
Quality, fact-based content is more important than ever to Google. The emergence of RankBrain is the culmination of many algorithm updates and refreshes to get Google to a place where it can return smarter results. Focusing on how-to content and answering the pressing questions customers have about your product/services is more important than ever.


I wrote in June that 2015 was the year of mobile (again). Google seemed to agree, and delivered a few mobile-specific updates this year worth noting.

April – In a historic moment, Google actually gave site owners time to prepare for their first major mobile update! Announced on February 26, Google said to ensure sites were mobile friendly by April 21 or you’ll regret it. The SEO community took notice, dubbing the roll out “Mobilegeddon.” After the rollout, Google would look at the following attributes to make sure if a page was mobile-friendly:

  • The page avoids software that is not common on mobile devices, like Flash
  • The page uses text that is readable without zooming
  • The page sizes content to the screen so users don't have to scroll horizontally or zoom
  • The page places links far enough apart so that the correct one can be easily tapped

This update was also executed at a page level, meaning if an entire site couldn’t be migrated to a mobile-friendly format, only pages that were mobile-friendly would see positive results in the mobile search engine results pages (SERPS).

May – Cinco de Mayo brought more than tacos and margaritas this year. It was also the day Google announced more searches now take place on mobile devices than desktop. By the end of the month (May 27 to be exact), VentureBeat reported app indexing on iOS devices was possible.

October – With app-indexing available on Android and iOS devices, Google publicly announced businesses who deploy mobile apps and use the new App Indexing API would see a ranking boost. SEO Roundtable also reported three tactics available in Search Console focused on app indexing:

  • The ability to segment out Search Analytics data based on clicks on the search result links versus clicking on the install app button.
  • The ability to fetch as Google not just using the APK version published on Google Play, but also by uploading an unpublished APK version directly through the fetch as Google feature.
  • The fetch as Google results will now also show the complete API response including title, description, API URL and more.

November – Google officially announced at the end of August they would slowly roll out the availability of three mobile ad slots in search results instead of two. Fast forward to early November, and mobile ads officially take up 50 percent of the mobile SERP. This update makes it harder for sites to show up above the fold organically on mobile devices, which is significant considering the announcement that more people search on mobile devices than not.

example of local SEO on iPhone screen

Google also announced on November 18 the indexing of app-only content. “Because we recognize that there’s a lot of great content that lives only in apps, starting today, we’ll be able to show some ’app-first’ content in Search as well. For example, if you need a hotel for your spur-of-the-moment trip to Chicago, search results will now include results from the HotelTonight app. Or if you’re thinking about visiting Arches National Park, you will now find details about the 18-mile scenic drive from the Chimani app.”

For example, if you need a hotel for your spur-of-the-moment trip to Chicago, search results will now include results from the HotelTonight app. Or if you’re thinking about visiting Arches National Park, you will now find details about the 18-mile scenic drive from the Chimani app.”

Related Articles: Get Found Faster: The Comprehensive Toolbox for SEO Marketing

HotelTonight app by Google

TL;DR Mobile Updates

Google made it clear this year mobile can’t be ignored. Non-mobile friendly sites will see a drop in rankings. Things like app indexing can provide a boost in rankings, increasing app downloads as a result. 


Not all major SEO news can be categorized. From local SEO to social, below are key takeaways from 2015.

February – Bloomberg reported Google would rekindle their partnership with Twitter. Throughout the year, Google would roll out tweets in real-time in the SERP. Once the rollout completed all tweets would be indexed by Google, making Twitter even more relevant for SEOs.

May – Our beloved Webmaster Tools (WMT) got a new name and features. Now called Search Console, it includes reports from WMT such as Crawl Errors, and new features like Search Analytics (replacing the search queries report). SEL reported on some of the new features of the Search Analytics report such as how it, “enables you to break down your site’s search data and filter it in many different ways in order to analyze it more precisely.”

May also began the official roll out of Tweets appearing in the mobile SERPs.

tweets appearing in mobile SERPs in Google

 August – Tweets officially rolled out to all devices by August 21.

tweets appearing in Google search

September – Local search got a facelift in the SERPS when Google replaced their 7-pack results with the new 3-pack or “Snack Pack.” SEL reported, “Searchers do have the option to click for more results, but this additional step will likely have a negative impact on local businesses ranked in positions 4–7.”

3-pack Google Maps results example

Related Article: Storytelling 101: What Defines Good Content for Off-Page SEO?
TL;DR Miscellaneous Updates
Algorithm updates and mobile should be top focuses moving into 2016, but things like social and local shouldn’t be ignored. SEO isn’t a one-factor show—it has a lot of moving parts. Keeping up-to-date on all changes can help boost your SEO programs.

Phew, if you made it all the way here, congrats! While this is a lot of information, hopefully, it serves as a great resource for remembering when a pesky update happened in 2015.

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