Many IS/IT departments are fully capable of developing Web sites, however, many prefer to hire an outside firm for initial site development or site redesign. The reasons are many: time/budget constraints, lack of artistic ability, benefits of having an "outsider" view the site and process as if a potential customer, benefits of having an "outsider" guide the process with competing departments and interests (eg my stuff is more important than their stuff). If you use an outside firm to develop your site, your IT staff should be an integral part of the development process. Their suggestions and input may be critical and their commitment to the project and ongoing maintenance are improved if they are involved upfront.