If your remarketing campaign is not getting enough impressions and clicks, you can make some changes to increase reach and ensure your ads are showing as much as possible. Since with remarketing you are reaching users who already showed interest in your website, your settings can be less restrictive while still reaching an extremely targeted set of visitors.
To ensure maximum visibility, try making some of the following changes:
Budget: Is your remarketing campaign consistently reaching or is close to reaching its daily budget? Try increasing it to get more impressions and clicks.
Bids: Increase bids to be more competitive in the ad auction against other advertisers.
Location and language targeting: Relax your location and language targeting settings.
Frequency capping: Try increasing impression caps (if you have frequency capping enabled) to increase impressions or how often ads show to each user.