FWIW, Here's a bit of marketing perspective (long post warning):
Across most categories, the retailer has margins of between 25 and 50% to play with. Franchised retail is usually at the upper end of that number and multi-brand at the lower end. This is why you can get a 15-20% discount on most products without any major issues. The MRP is a notional figure that assumes that people will ask for a discount, so it includes sufficient margin. For example, look at the printed MRP on a motherboard or processor and compare it with your bill. Most other categories, specially where importing is concerned - which is 90% of all goods - sees almost exactly the same figures.
This also means factory stores and franchises don't hurt when sales are offered at 'Flat 40% off'. That 40% is not a loss making figure, it forgoes most of the net margins for higher realisation due to volume. There is still a 5-8% margin that remains and if you triple volume (a very conservative figure) you end up making more money than regularly having to give a 20% discount. The issue is that traditional retail has had years of comfortable living where MOPs and hard floors on pricing are the norm. Online is not bound to follow the same rules.
The problem that traditional retail has is twofold. One is total sales, which is the smaller problem, and basically comes from the fact that we are in a recession and liquidity has dried up. Hard cash is tough to come by and the typical Indian does not buy as much on credit as on hard cash. This means that shopping money is much smaller than it used to be. Fortunately, online retail is still a miniscule fraction of traditional retail so this problem is not as big as it seems except in certain categories. If the electronics industry has seen a growth of 4% and the online market is 5% of traditional retail, it would mean a maximum of 1% of cannibalisation.
The bigger problem is that all the VC money that is flowing into the e-com portals is being spent on marketing and customer acquisition. It is a mindspace problem - basically creating a fork in the consumer's mind that online is cheaper and a good place to shop. It isn't always true, but over time this impression can be created. And this would bother traditional retail most of all, as it is competing for future business. Unfortunately, it is a problem they have created to begin with. Undercutting is one of the prime tools of B/M retail, and they've been doing it for years. It is the very reason that brands stepped in and began to formulate and enforce MOPs. In most countries, the MOP guidelines from India would amount to unfair trade practice. And even manufacturers are not totally clean when it comes to discounting product, except they would never do it directly.
Samsung and LG etc have been doing this for years with their 'scratch card' and similar schemes. For example, If I had to spend 50cr on a campaign for one sale (for scale, an election campaign for a political party can be expected to cross 500cr), I would spend about 80% of that on dissemination and 20% on the 'gifts'. All FK did was discount the products directly, and that is what got the retail industry's goat. Discounting your product 'cheapens' their image, and that is why they are sulking. None of them have got with the program, that brands mean nothing, it's basically product feature and price that ignite the purchase decision. After all, everything is made in some cheap sweatshop in China with workers in horrible conditions at the lowest pay, and all are designed to last exactly as long as the warranty.
As for the moaners, I am pretty sure FK didn't promise that everything on sale would be offered for an unlimited time to all comers. It was very clear that the sales would be on a limited quantity of products and for a short period of time. So maybe 5-10% of all in-stock items would be offered at a special price. Therefore it's like a lottery, if you get it well and good if not, better luck next time. You should see how riotous the situation gets in the US outside Apple or Sony stores when a new iPhone or Paystation launch (typo is intentional), and how people shop on Black Fridays (actual violence occurs). Not everyone ends up lucky. The typical Indian mentality of entitlement is rife in all the negative comments I read (technical issues aside, those are real problems and I faced quite a few).
Personally, I'm chuffed that I snagged a pair of 770s at a massive discount, but I was also pretty sure they wouldn't fulfill the order. Was quite taken aback when I saw they shipped it, but I'll believe it when I see them doing SLI