The first thing you need to do is find out what are the most searched keywords for your product, and there are a few ways to do this. Amazon gives you the option to run an automatic PPC campaign, or a manual PPC campaign, for your product. You should start with an automatic campaign first, Amazon will do most of the work for you, including choosing which keywords best suit your product.
Once the automatic campaign has run for a week or two, you can check your advertising report to find out how well your campaign is working so far, but more importantly, to find out which keywords are the most useful. Once you have discovered that information, you can then use the keywords with the highest conversion rates in your manual campaign. Don’t cancel your automatic campaign just yet, though, if you leave it running, it can continue to source good keywords for your manual campaign.
As for that manual campaign, it gives you more customization than the automatic campaign because you can choose your own keywords. Those keywords can be taken from your automatic campaign or from a keyword search tool. Once those keywords have been chosen, you can then use them in three different ways
Broad – Your keyword will activate on any search that includes those words even if they are non-consecutive. For example, if your keyword is “jump rope,” it will activate for search terms like “jump rope for men,” “jump rope for women,” “jump speed rope,” “weighted jump rope,” and so on.
Phrase – The keyword will get activated for any phrase that includes it, so search terms like “jump speed rope” will not be activated.
Exact – Your keyword will only activate when people search for it exactly, so it will not be activated by search phrases like “weighted jump rope” or “jump rope exercises.” Only the term “jump rope” will be activated.
*Note that you can include certain parameters in each type of search, you can allow them to include plural or singular searches (jump rope and jump ropes) as well as misspellings, acronyms, and abbreviations.