In the latest issue the Fast Company magazine describes the database used for Amazon's Search Inside the Book feature. It includes 120,000-plus books. Each one had to be scanned digitally and indexed, a huge logistical challenge at a huge cost. The database took up 20 terabytes, which Bezos says is about 20 times larger than the biggest database that existed anywhere when Amazon was founded. But a large-scale launch was the only way to see whether it would go over with Amazon's 43 million active customer accounts.