How to use Flipkart Plus feature for free ?

What is Flipkart Plus service and how to get it for free? Check out this Ask Expert thread to know more.

Some of my friends got the option to upgrade to Flipkart Plus for free ? How can I also make use of such an option.

Otherwise, is there any way to get this service on discount like for 505 off or so? What are the benefits of this service and how long will it last ?