My first ever online purchase was made through Flipkart. I liked the services quite a lot, and since then I have become a fan of online shopping most of my shopping is done online. (though not necessarily from Flipkart)
I have not found many discounts and offers coming from Flipkart, but I have observed them to provide a market rate at least Rs100-200 less than most others.
I would recommend using Flipkart in the following two scenarios:
When you do not find a good offer on any other site which makes the product cheaper than flipkart.
When you want a reliable and fast service. Their delivery time has been comparatively less than most sites I visited.
Also it is a good site to find a reasonable base price for a product before comparing the prices with other sites.
I never needed to contact their customer care so I cannot comment on that but I did read mixed reviews of customer care in reviews below.Overall I love both price and service of Flipkart.