Flipkart has complete control over their products right from the order, till the dispatch with their own-delivery system.
In my experience, most sites ship their orders, a day or later after you place an order. But, flipkart ships their orders in a same day, based on the availability..
That's their USP. After all, Customers were/are/will be the GODS.
But nowadays, flipkart is bit pricey on some items - especially on electronics.