SEO retainers usually trap you at 30 percent margins because you’re selling...

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

SEO retainers usually trap you at 30 percent margins because you’re selling time. By turning your internal scripts into your own software, you can push those margins past 70 percent. Treat your agency like a lab to build your way out of the grind.