I think their base model is validated, it just may need more. According to the TC article [1], "In a statement, Flipkart said the 'funds will be used to make long-term strategic investments in India, especially in mobile technology.'" So they are predicting some of these acquisitions to help grow that model before going public.
[1] http://techcrunch.com/2014/07/29/indian-e-commerce-giant-fli...