The End Of Summer Blowout Sale is a sale that lasts from September 2, 2011 to September 6, 2011 (6:00 PM PDT) during the Labor Day weekend. During the sale, the prices of a number of different items were lowered, some having up to 60% off in savings.
The sale was temporarily stopped on Saturday, September 3. This was because of a bug that if players bought an item at the sale price, they could sell it before construction at the regular price. As a result, a lot of players used this to their advantage to get a great deal of coins. Later that day, Zynga patched the bug, and took away all the coins players had gained, back down to what the players had before they found out the bug. However, players were still able to keep any items they had bought with those coins.