Many factors contribute to the fluctuation of Facebook Ads CPM. Competition plays a major role. During busy seasons like holidays, more advertisers bid for ad space. This increases costs. Ad relevance matters too. Facebook uses a feedback score based on user interactions. A low score raises your CPM. Target audience affects costs. If your audience is too broad or not engaging, your CPM will rise. Ad frequency can also impact costs. Showing the same ad too often leads to fatigue and higher CPMs. Monitoring these elements helps manage fluctuations effectively.