Hashtags are flexible, non-linear and anarchic. Any internet user can create a new one or put an already established hashtag into a new context and thereby change its meaning (e.g. #Outcry). There are no rules for correct use, but they only gain meaning when they are used by more than one person.
This makes them an expression of a collective consciousness (I use consciousness as opposed to intelligence because it seems more neutral to me). This makes them very interesting for Google, because as a semantic search engine it has set itself the task of better understanding and classifying content.
Semantic classification of entities
On the surface, this article is a summary of how and where hashtags are used in Google. The underlying assumption is that Google uses them as part of its own semantic understanding.
Hashtags could be used to understand the context of content, but they could just as easily be used to understand the main topics of entities . An entity (people, brands, companies, etc.) that is regularly tagged with the same hashtags by many people could serve as a signal for Google to classify topics.
hashtags and entities
Hashtags are mainly used on Google Plus and the example shows how they can be used to link entities to other entities.
Hashtags on Google Plus
As with most other social networks, Google Plus allows you to add hashtags within a post to connect that post to a specific topic. In this example, an article was shared and tagged with #shopseo and #seo.
Google's hashtags1
Google then generates a hashtag label at the top right of the post with a gray mark on the side. If you don't like this, you can delete this label by moving your mouse over it. An "x" will then appear on the side. The hashtags within the post remain and can still be clicked by other users.
Google also assigns hashtags independently
Furthermore, Google also adds hashtags on its own and marks them in blue, even if you haven't specified any in the post. When Google adds hashtags to a post on its own, they are usually terms that appear somewhere in the post, either in the body text or in the URL that you share.
Google's Hashtags2
However, I also found an exception where Google assigned a hashtag on its own without being triggered by a keyword in the text or URL.
Google's hashtags3
Google has added #seo here and that is quite appropriate. Google has therefore recognized from the terms Schema.org, Hummingbird and Markups that this is about search engine optimization in the broadest sense . It probably helps that both I and Aufgesang , whose post I shared, regularly post about SEO topics. I also have a lot of SEOs in my circles, so Google "knows" that I am interested in it.
Related Google Plus Posts: Keyword Research of Tomorrow?
If you now click on the hashtag label at the top left, the bosnia-and-herzegovina phone number data post rotates and a related post selected by Google appears, with a slider with the corresponding hashtag above it. The slider presents four more related posts until finally a whole list of topic-related hashtags appears.
hashtags on Google
This is not entirely uninteresting because it shows how Google relates certain topics to each other. Hashtag searches could therefore be an interesting part of keyword research .
trending hashtags in the search results
As briefly mentioned above, hashtags are flexible. They can be very short-lived, for example, but can be used intensively. Just like Twitter, Google also registers hashtag trends, which are then even shown in the search results. When I googled #panda on the morning of May 22, 2014, I got the following result:
#panda Google Search
I was no longer able to reconstruct the result that same evening. It was also noticeable that the animal appeared prominently again and there was no longer any cross-reference to Twitter and Facebook.