Let's say you find the keyword "rope" inside your STR by doing a regular analysis and pulling out search terms from your broad, phrase, or auto campaigns.
What a lot of Amazon sellers would usually do is create a separate exact campaign.
However, this is not a very efficient and helpful practice for your product ranking as broad keywords are very generic and have little buying intent.
Not to mention that you hurt the metrics that are important for ranking such as CTR, and CVR because the customer might have expected something else than what your product offers.
Instead, you would want to create a new broad match type campaign using the keyword that you found in your STR prior, "rope".
The goal is to find new, high-relevance, long-tail keywords that you can then allocate into their own, separate campaigns.
You will slowly start to notice different search terms popping up in your STR next month such as "2ft rope", and "blue 2ft rope" that you can implement in your exact match campaigns.
This will help you increase the CTR and thus help you rank higher on the Amazon paid search results without necessarily having to bid more on a particular keyword.