One of the biggest problems with hourly billing is it assumes that time spent equals value, but that assumption is incorrect. In fact, the opposite is usually true – it is almost always more valuable to have the results faster.
Imagine you hire a kid to cut the lawn at your house and you agree to pay him $20 each time. The first few times, he shows up with a push mower; it takes him about an hour and you pay him $20 each time.
One day he shows up with a fancy ride-on lawnmower and cuts the grass in 30 minutes. The job is done just as well, but faster. Do you pay him less?
Now imagine your car is having engine issues. You take it to the mechanic, who spends 8 hours trying to diagnose the problem.
When you go to pick up your car at the end of the day the mechanic tells you he spent 8 hours on the problem but wasn’t able to fix it. He hands you a bill for the 8 hours he spent. How do you feel?