Traditional retainers stall at 30% margins because of the manual work required...

https://dibz.me/blog/why-a-handful-of-european-seo-agencies-stopped-being-agencies-and-1138

Traditional retainers stall at 30% margins because of the manual work required to deliver results. If you turn your best processes into internal software, you can easily reach 70% margins. Treat your agency like a lab and start scaling your own products.