We all know by now that semantics (understanding the meaning behind language) is a key part of Google's search engine algorithm and integral to showing relevant results. After all, it's the difference between seeing a list of DIY stores or the latest hits from an American rock band after searching for "nine inch nails."

Semantics also powers Google's suggested search feature. Imagine a web of inter-connected search terms; some of which will be slight variations on one another, some will be different but still part of the core search topic. Google is able to see that a page focused on one topic may be relevant to a variety of related but different search terms.

Then we've got traditional SEO tools, such as Majestic, that have been measuring topic authority for years and providing those metrics to subscribers of their tool. The topics it uses are fairly broad (i.e. one topic might be Computer / Internet / Cloud), going from broader topics to more specific ones.

All this shows is that topic authority as a concept has been around for a while, but really it deserves more attention than it's been given.

Matthew Barby, in his article below, has highlighted the importance of changing the way digital marketers craft their strategies. Whether you have been focusing on a handful of top-level, high-volume commercial keywords or sporadically targeting long-tail keywords, you need to re-think what you're doing.

Look at topics - or what Barby calls 'topic clusters' - that are made up of a core topic and a large number of related sub-topics. Not only does the effort you put into any part of that topic cluster benefit the rest of it, but it helps to build topic authority.

From an SEO perspective, building up topic authority is an efficient and effective way of increasing organic traffic (if there's decent search volume around your topic cluster).

From a content marketing perspective, topic authority builds brand authority (as long as the topics are aligned with the brand and your personas) as well as leads.

So, the concepts of topic authority and topic clusters represent a tangible, beneficial convergence of SEO and content marketing. It seems the lines are blurred even further (sorry about that!), but that's why integrated marketing teams are so important.