The Perverse Incentive in Hourly Billing
Let me be direct about something most agencies won't say out loud.
When an agency bills hourly, they make more money the longer the project takes.
Think through what this means in practice:
Slower developers aren't a problem for the agency. A junior developer who takes twice as long to implement something as a senior developer bills twice the hours. For an hourly agency, this isn't a quality problem, it's a revenue opportunity.
Scope creep doesn't hurt the agency. When you add a feature, or change your mind, or expand the requirements mid-build, every hour spent on those changes is billable. The agency isn't incentivized to push back on scope changes. They're incentivized to say yes.
Complexity is rewarded, not penalized. An over-engineered solution takes more hours to build than a simple, elegant one. For an hourly agency, over-engineering is more profitable than simplicity.
Timeline estimates are padded. Every experienced developer adds buffer to their estimates. For hourly billing, that buffer is billable. A two-week estimate quietly becomes three.
I'm not saying agencies that bill hourly are dishonest. I'm saying the structure creates incentives that are misaligned with what you actually want: fast, lean, right-sized.