A freelancer is useless without a good portfolio, and to maintain clients, a high standard is a continual requirement. A freelancer is directly responsible for every piece of work produced, and every job must be treated as such.
Multiple skill sets, not being restricted to what is already understood and practiced. A freelancer will work from start to finish, adapting and specialising in all aspects of the project, not just filling in a position on a production line.
Freelancers are adaptable to deadlines, and able to undertake jobs in a lesser time frame as they are the only person that needs to be available for a project. Freelancers are also more available, often working outside the traditional working hours and are less susceptible to distractions from co-workers or company politics.
A freelancer is his/her own boss, and can use their own discretion to make decisions based on the circumstance, not policy. They have experience with a large variety of tools, able to adapt to the project at hand. Freelancers pride themselves on high availability, the ability to work on projects outside of office hours.
A freelancer is not a Salesman
A freelancer seeks a continued relationship with your business, and intends to make a difference. It is in a freelancer's best interest to make your project successful, and their interests go far and beyond getting proposal approval or making a sale - the freelancer is there with you every step of the way.