A travel agent is often most loyal not to you, but to a travel supplier, such as an airline or tour operator. This is because the travel supplier and the travel agent have an ongoing relationship -- the agent represents the supplier and is compensated for providing business to the supplier.
You may feel that a travel agent should be your agent and should look out for your best interests, rather than the interests of travel suppliers. A good agent will take on this role, knowing that good customer service will lead to repeat business. In addition, the law is changing in this area, and sometimes a travel agent may be considered your agent as well. In most cases, however, the travel agent will owe you the normal duty owed by a salesperson to a customer, but no more.
When a travel agent issues a ticket or makes other travel arrangements for you, the agent sometimes receives a commission from some travel suppliers such as a tour group or hotel. However, airlines pay virtually no commission these days.