Amazon India

Losses

2016 - 3571 Cr.

2015 - 1723 Cr.

2014 - 321 Cr.

Source:The Economic Times dated 20/01/2017. Figures are for Financial Years

Flipkart

Losses

2016 - 5223 Cr.

2015 - 2979 Cr.

2014 - 914 Cr.

Source:The Economic Times dated 20/01/2017. Figures are for Financial Years

Snapdeal

Losses

2016 - 2960 Cr.

2015 - 1319 Cr.

2014 - 264 Cr.

Source:The Economic Times dated 20/01/2017. Figures are for Financial Years

Big Basket

Losses

2016 - 277 Cr.

2015 - 61 Cr.

2014 - 21 Cr.

Source:The Economic Times ET Tech dated 05/01/2017. Figures are for Financial Years

The short answer.
We don't wish to lose money!