How Broad is Extended Broad Match?

This article continues from my previous article on AdWords Unexpected Match Types.

I have recently discovered a very simple way to determine just how broad Google’s Extended Broad Match Type is in Google AdWords.

Using Google Search you can easily determine which keywords Google considers synonyms which is a feature of the Extended Broad Match Type. By using the “~” character before a word enables you to see synonyms of that particular keyword. By also including the “-” operator we can eliminate the visibility of the original keyword, therefore displaying only the related synonyms.

Let me give an example. In my previous post I gave the example of the keyword ‘hong kong night life’, showing ads when someone searched for ‘hong kong sex’. This was a most unwanted result and was resolved by way of a refund from Google for the costs incurred from people clicking on my clients ad which had nothing to do with ‘hong kong sex’.

Now, if we go to Google.com and type in ‘~nightlife’, we get 1.6 billion results, mainly displaying the term ‘nightlife’, ‘club’ and ‘clubbing’ highlighted in bold.

The next step is to remove those terms that we can see in bold, in order to narrow down all the synonyms until we reach those that we most likely, do not expect to see. All those keywords that we add as negative keywords are keywords that Google deduces to be synonyms of the original term. When we are left with no remaining search results we will have a list of all synonyms of the original search term.

Lets remove those that we can currently see. We will add ‘-club’, ‘-clubbing’ and ’-nightlife’ from the original search term ‘~nightlife’.

This leaves us with 920 million results, the most popular being ‘guide’. Removing ‘guide’ leaves us with 105 million results and removal of the term ‘bars’. 2 million results and ‘nightclubs’ to be removed.

This is where it becomes interesting. After having removed ‘nightclubs’, we are left with results for ‘escorts’. This clearly shows that Google associates ‘nightlife’ with ‘escorts’.

By adding ‘-escorts’ we can see that there are no remaining synonyms of ‘nightlife’.  Therefore, as ‘escorts’ are similar to ’sex’, the advert triggered by the keyword phrase ‘hong kong nightlife’ was subsequently displayed.

The conclusion therefore is very simple. Extreme caution should be carried out when only using the broad match term in Google AdWords. Any terms that you suspect may result in unwanted ad visibility must be investigated thoroughly to ensure that they do not trigger ads to be displayed on terms that are entirely irrelevant to a users original search query.

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This entry was posted on Thursday, September 27th, 2007 at 1:28 pm and is filed under Google AdWords. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.