Most SEO retainers max out at 30 percent margins because you are trading hours...

https://www.first-bookmarkings.win/stop-trading-your-time-for-low-margin-retainers-that-hit-a-30-percent-ceiling

Most SEO retainers max out at 30 percent margins because you are trading hours for money. Turn your best internal workflows into a simple tool and shift your focus to 70 percent software margins. It is the best way to scale your agency.