Agency retainers usually top out at 30 percent margins because you are tethered...

https://wiki-net.win/index.php/How_to_Keep_Pricing_Accessible_for_Small_Agencies_Without_Undercharging

Agency retainers usually top out at 30 percent margins because you are tethered to headcount. Treat your agency like a lab to break that cycle. Productize your internal workflows into SaaS tools and watch your margins climb past 70 percent.