The answer should be YES to all 3 above, otherwise, your ads will not receive any impressions.
Is there an error at the campaign or ad group level? This needs to be checked on Seller Central. Are your ads (products inside your Ad Groups) “Pending Review“, “Not Eligible“, “Error“, etc.
When creating your PGN, have you added SKUs or ASINs? You HAVE to add SKUs. Amazon will ignore any ASIN added
Do you have active keywords? Check your PGN at KW level and see if you have Keywords and if they are active
Are you bidding high enough? If you are not receiving impressions, your bids might be too low. Although Bid Gambler will periodically raise your bids chasing the first click, you might speed up the process by increasing your bids manually
Is your Auto Campaign bid too low? If your Auto Campaign ACoS is way higher than your target Max ACoS, we will drop the bid, and sometimes our calculated bid might be too low to gain impressions
Are you bidding on the same terms in other campaigns? Amazon algorithm likes history and will prefer to give the impression to an older keyword
Is the product still in the same sub-category or did it get moved? Categories affect which product can win the impression
Having said this, we have an automation that is specifically designed to periodically raise your bids until you achieve your first click.
If any of this doesn’t work, try choosing “Fixed Bids” (Seller Central, Campaign Settings) and see if this helps