All their server issues must mean they are dealing with unprecedented demand. It makes me wonder: When demand is THIS intense for a 75% off sale, you think it'd mean a more optimal "normal" price point would be at 25-50% off your current normal prices, wouldn't you?
For example, Steam sales. When I see a game that is interesting I will think "cool, but I should finish all of the games I'm currently playing first". If I have 24 hours hours to get it at half price it feels like I am actually saving money in the long run even if I don't play it straight away.
Whether it was worth the initial price or not is almost irrelevant. I imagine if they set their prices to 25% permanently there would still be high demand if they did a further 25% sale.