If you need a perfect translation, only a human being can assure you of getting one. On the other hand, human translators cannot do instant translations. And although human translators can perform free translations, the best of them rarely do so. For reasons of speed or price, many of the fastest-growing needs for translation can only be met by Machine Translation. Machine Translation is also great for searching document archives in other languages for the document you need, and then getting a quick, rough translation of that document once you've found it.
Human translators excel at creating perfect translations.
If you are going to print or publish your translation, you definitely want the translation done by a competent human translator who has experience in that particular domain, such as we provide with our PremiumPlus translation service level. Use the right tool. You can't afford a human translator sitting next to you as you look around the Internet or your company Intranet for the information you need. On the other hand, you don't want to use Machine Translation to translate your company brochure from English to German, then print it and send it to a prospective client in Berlin. This is about 5 pages of a word processing document.