Running ads for dozens of e-com brands, I see the same mistakes over and over. Here are the top 3 that are probably costing you money right now:

1. Scaling too fast on a winning ad

You find a winner doing 3x ROAS and immediately 5x the budget. The algorithm panics, CPMs spike, and your ROAS tanks. Instead: increase budget by 20-30% every 48 hours. Let the algorithm adjust.

2. Testing too many variables at once

New creative + new audience + new copy = no idea what worked. Test ONE variable per ad set. It's slower but you actually learn what converts.

3. Ignoring post-click experience

Your ad can have a 5% CTR but if your landing page loads in 6 seconds or your product page is confusing, you're burning money. Check your landing page conversion rate before blaming the ads.

Most brands I work with are leaving 30-40% of their potential revenue on the table just from these three things. Fix them and watch your numbers change.