At Sun there was literally a taped square on the floor of the factory, and things in that square were "shipped" to as the quarter was finishing up the factory would figure out how much had to be shipped to make the numbers, and they would process enough orders to make that happen. If there weren't orders, then some "one time deals" would be mentioned to top customers who might get a really nice discount or something. Sometimes contractors are told to go home until the next quarter.

At NetApp there were other tools, service revenues, expenses, etc. One quarter the call went out for everyone to be sure they had expensed everything they had outstanding. Once the summer employee event shifted by a week. They would also do close the quarter incentive sales which could bring in just enough orders to keep it in line.

As far as I can tell this is something they teach in business school as part of your MBA training. It seems pretty universal. When things can't be managed that way, you get actual unexpected surprises, lay offs, or work furloughs, or perhaps you decide you aren't going to hire nearly as many next year so you trim all the contract staff.

Clearly people aren't as worried by over delivering as they are under delivering. As you can see from the Apple and Google earnings calls, a small miss negative can have an outsized impact on your stock price. But it is also important to not consistently have upside surprises as suddenly people start valuing the stock assuming an upside surprise.