This is definitely a very good news for all Gmail users from India. From now onwards Google users from India will be able to send SMS (Short Messaging Service) to an Indian mobile phone from their Google Account.
Google has basically stuck a deal with various telecom operators to launch this service. Nearly all of the Indian based telecom operators are covered within this deal but there might be some regions where you will not be able to send SMS even when the operator is supported. Supported operators includes Airtel, Vodafone, Reliance, Tata DoCoMo, Idea and Aircel.
This service from Google is slightly different from the SMS service offered by Yahoo. In this every user will initially get 50 credits for his or her account. With 1 credit you can send one message to a mobile. Credits will continue to deplete as you continue to send messages. They can be replenished only when the person to whom you are sending SMS replies back to your Google account. If he or she replies back than Google will credit 5 units to your account. At any time the maximum number of credits with a normal Google users will always remain 50. In case if some user didn’t receive any replies and consumed all the 50 credits then after 24 hours Google will credit their account with 1 unit so as keep them in the game. Presently there is no way of purchasing credit from Google.