Back in the day when software came in shrink-wrapped boxes, many companies bought more than they needed in order to make sure they had enough licenses for all their employees. They stored the unused software on shelves in storerooms, and over time, it became known as "shelfware."
The advent of cloud computing was supposed to mark the end of the need for shelfware, but experts like Upfront Ventures general partner Mark Suster are noticing that companies are still overprovisioning. It happens because companies sign up for volume discounts that give them more capacity than they need, because people forget to turn off cloud instances when they are done with them or because IT managers don't really understand cloud computing and manage their cloud resources the same way they would manage a traditional data center.
This sort of overprovisioning in the cloud can lead to a lot of waste. And it's a big enough problem that a new group of startups is promising to help enterprises find and turn off unused cloud resources.