This can be due to a few things. Here are some of the most common situations and what to do about them.

  • Low Bid - If your bid is too low, Amazon won't show your ad. Try increasing your bid
  • Another one of your keywords is winning - If you have the same keyword in multiple campaigns, Amazon will chose one of them to enter into the auction for the impression. If one keyword has a higher bid, it's likely going to be the only one ever entered leaving the other keyword with low or 0 impressions. Try pausing other keywords that get exposure for the search terms the problem keyword can fire for and see if you get any impressions. You can also try increasing the bid higher than all of your other keywords.
  • Your product isn't relevant - If Amazon doesn't think that keyword is relevant for the product you've selected to advertise, they won't show it. Make sure you're bidding on relevant keywords.

If all of these fail, it's possible Amazon has a problem with this campaign, ad group, ad, or keyword. If it is in fact a problem on their side, they'll admit it and fix the issue.