SEO retainers usually cap your margins around 30% because the work never gets...

https://bizzmarkblog.com/what-mistakes-do-agencies-make-when-they-try-to-ship-software/

SEO retainers usually cap your margins around 30% because the work never gets easier. If you turn your internal scripts into simple software, you can easily hit 70% margins or more. Treat your agency as a lab to build your own scaling tools.