By providing more than just a person to provide the service, such as having liability insurance and a pool of providers. They also likely have disincentives for

By providing more than just a person to provide the service, such as having liability insurance and a pool of providers. They also likely have disincentives for the people providing the service to make deals on the side. This is why consulting companies avoid evaporation. Additionally, in the case of the pet service, they may make much of their money on one-time transactions, say for people travelling.