What should I audit first when my paid ad campaigns have high cost per acquisition and falling conversions?

Start by auditing your session logs and conversion tracking setup to identify where data drops off between your website and ad platforms. Check whether client-side pixels are being blocked by privacy tools, verify that your landing pages maintain message match with the original ad creative, and confirm that your bidding models are receiving complete conversion signals. Fixing these foundational leaks usually yields faster ROI improvements than tweaking bid strategies alone.