Technology can feel like magic, but none of it appeared with the swipe of a wand. Things like Google, iTunes, WebMD and Facebook all came after other companies had similar ideas, but failed to prepare them for the long haul. Whether it was timing, management, or ego, sometimes the smallest cracks led to the fall of great ideas—and one startup's mistake is another's opportunity. Here we highlight 10 classic startups that failed, but should have succeeded. Hindsight is always 20/20.