Most SEO retainers max out your margins at 30 percent because of the heavy...

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

Most SEO retainers max out your margins at 30 percent because of the heavy labor involved. Turn your internal scripts into simple tools instead. You’ll stop trading hours for dollars and start seeing software margins north of 70 percent.