You already ran the math. On a $250K job where two problems ate the margin, your net dropped to $30K. If they had taken 12% of top line, you'd have worked 6 months for zero.
The other agency wanted a 12-month lock. You don't sign contracts you can't test first.
Both wanted to run your finances and credit cards. Not happening.
$2,000/month flat retainer. No percentage of your revenue, ever.
Month to month. No 12-month lock. If we don't perform, you walk.
Your ad spend goes on your card, not ours. You keep control of your money.
You own the ad account, the pixel, the leads, all of it. Fires us? You keep it all.