Machine translation (MT) is a branch of computational linguistics which checks the use of computer software to translate text or speech from one language to another.
Quick Translation: The use of the machine translation system allows a person to save time when translating large texts.
Low price: If a text is translated by professional translator, then enough money should be paid for each page but sometimes just a point of matter is required like general idea. In this situation, machine translation system is more reliable and effective.
Confidentiality: Most of the people make use of machine translation systems to translate their private emails. Because, no one would feel to give his private mails to translator who is not known, or no one would hand over financial documents to other people.
Universality: Generally a professional translator will be specialized in a limited and a particular field, but machine translation system can translate any text regarding any field. In order to translate special terminology, just switching to a corresponding setting can be done.
Online translation and translation of web page content: The benefits of online translation services is prominent. Online translation services are easily accessible and can translate information quickly using this service. Moreover, translation of any web page content and query of search engine can be done using machine translation systems.
The problem that I see with using a technology based translation service is that you cannot replace the experience, knowledge of cultural references and knowledge of accents and dialects that can be brought to translation carried out by a professional (human translator)
Also, my exerience of using Google Translate has made me rather sceptical of how good a machine based translation service can be.