There has been debate for some time now regarding whether or not bidding on multiple match types for the same keyword is an effective strategy or not. An example would be purchasing:
Bradford PA Restaurants
”Bradford PA Restaurants”
[Bradford PA Restaurants]
In this case the advertiser would be attempting to purchase the same term in Broad, Phrase and Exact match types. Regardless of whether or not they are in their own ad group, all terms would be turned on in an attempt to serve an ad. So why would anyone do that?
I recommend using this strategy for testing purposes. Not all match types are perfect for all keywords. Sometimes an exact match type will carry a slightly higher CPC, but you will likely not be spending money on wasted clicks as often found by using broad match. But, yes there is a but, broad match can be a great tool. It can help you find new keywords to purchase as well as allow you to build a more significant negative keyword list if you intend to stay away from exact match.
Depending on the account structure, I will start by placing the keywords in their own ad groups, sometimes even their own campaigns. This can help with bid and budget management and will be easy to clean up when you stop purchasing all match types. According to Google:
If you have multiple keywords that are the same, the system will prefer to use the keyword with the more restrictive keyword match type.
Therefore, depending on the queries that are driving traffic, your broad terms will only be served to users that aren’t searching the exact term or using the phrase as part of a longer query (theoretically). In testing, you may find that you are getting the majority of your conversions from the less restrictive match types or vice versa. But because search is a data driven marketing strategy, why not gather all the data you can get; including which match type performs better for you. And again, even if you are nervous about broad match it can really provide some great search query reports to help you build your account with high performing keywords, or expand your list of negatives.
In conclusion, my opinion is that bidding on multiple match types is a great testing and data gathering strategy, but not necessarily a long term solution. I am a firm believer that if you can gather data to improve your account performance long-term, trying various tests aside from the simple A/B test is a good practice.