Most retainers cap your margins at 30% because human labor is hard to scale....

https://www.tumblr.com/weepingmountainzealot/815686865347854336/serp-scraping-at-scale-what-does-an-agency

Most retainers cap your margins at 30% because human labor is hard to scale. Start turning your best internal workflows into software products instead. When you build a lab instead of just an agency, your margins can easily jump past 70%.