Keyword Match Types
Keyword match types determine which searches will cause your ad to appear. Each keyword will have a match type within Adwords which controls how loosely or restrictively you want it to match your ads to keyword searches.
There are four match match types currently available in Adwords:
The default match type is broad match, which will show your ad for anything search query that Google sees relevant to your keyword. For example if your keyword is trainers and is on broad match your ad will appear if someone types in boxing trainers or footwear as Google sees these searches as relevant. We would never recommend broad match as you are you are targeting too much of a wide audience, which is going to result in wasted clicks and budgets. For example if you are a business who sells and repairs tennis rackets and you have your keyword tennis rackets as a broad match keyword then your ad will show if someone types in tennis shorts or tennis headbands. However the business does not sell these products therefore people clicking on your ad are essentially wasted clicks and wasted budget. Google uses broad match as the default keyword match because broad match targets a wider audience, which mean more clicks, which means more money for them. They are a business at the end of the day!
Modified Broad Match
You have slightly more control over when your ads are shown with broad match modifier compared to broad match. In order to use broad match modifier put a plus before a word and this means Google will show your ad for anything it thinks is relevant but it has to include the word with the plus before it. For example if you are a business selling wheelchairs you could use broad match modifier and use +wheelchairs as your keyword. This would bring up your ad for searches like lightweight wheelchairs, electric wheelchairs, but wouldn’t bring up your ad for searches like mobility scooters or stairlifts which broad match would have done. However this match type could also cause wasted budget as if you were just selling normal wheelchairs, Google would still your ad for electric and folding wheelchairs which would result in wasted clicks. We use modified broad match in certain scenarios, however we prefer to use the two match types below much more.
Phrase match gives you much more control, as your ad will only appear when a user searches your keyword phrase using your keywords in the exact order you enter them, but there might be other words either before or after that phrase. Phrase match is used in Adwords with quotation marks. For example if you have “pet supplies” as your phrase match keyword phrase, your ad will still show for cheap pet supplies or pet supplies wholesale, however it will not show for pet hamster supplies or animal accessories. This gives us a lot more control over which searches our ad appears for, which allows to target our ads to people who are actually searching for our products or searches.
Exact match gives you the most control of when your ad shows. Your ad will only appear if someone searches your exact keyword phrase. This is shown in Adwords with brackets. Therefore if you keyword is [black nike trainers] then your ad will only appear if people search this exact phrase. This is the most restrictive match type, however by using this you are making sure people who see your ads are definitely your target market. However the problem with just using only exact match is you might not get your ads showing much and therefore your Adwords campaign might not be getting many clicks. There we at Siren Search use a mixture of exact and phrase match so that we might sure are campaigns are getting enough clicks but these clicks are also very targeted and therefore no budget is wasted.
I understand that this article is quite detailed, however as a sort of a high level summary I would suggest that if you are building an Adwords campaign from scratch I would suggest starting with phrase and exact match keywords and add any negative keywords in order to build a targeted, granular and effective campaign.