This usually points to a problem with the landing page rather than the ads themselves. If people are clicking but not taking action, something is stopping them after they arrive. The page might load slowly, the offer might not match what the ad promised, or the form might be too long. It is also worth checking if conversion tracking is set up correctly, because sometimes the conversions are happening but not being recorded. Have you ever found that your tracking was broken when you thought your campaign was underperforming?