Absolutely! Dressing for success is important for yourself personally, for the organization you are representing, and also, to be used to respect the person who were are interacting with.
Importance personally - I think in today's market place, we are always "selling" and networking, and therefore presenting yourself is PR. It is also important to note, that 80+% of communication is non-verbal, so the importance of professional attire should not be underestimated.
Importance to the Organization - As a representative of an organization, you are sending a message of the professionalism of not only yourself, but the entire company. And negative PR or bad image is completely unnecessary. I was once taught, that everytime a person has a positive sales experience, she/he will share the experience with 4 other people within her/his network of friends and family. But, a negative sales experience will yield to sharing the experience with 11 people in the network!
Importance to the person you are interacting with - you can never fully know the cultural, religious or personal values of a new person you are interacting with. Depending on various cultural backgrounds, an inapproapriate dress code can be viewed many ways. Therefore, playing it safe and dressing for success will eliminate a lot of unnecessary assumptions or lost sales.
Heli Rytkonen