We have learned that a big part of the motivation or benefit for going to the cloud is agility. Call it flexibility or scalability if you want, but “agility” is a bit broader and evokes the principles of the Agile movement. The cloud allows you to try something, fail, and move on to something else with relatively less severe consequences. The cloud does not require you to calculate with high accuracy the amount of resources you will need, or the length of time you will need them. You should be able to scale up and down, to add and remove services, to get the latest updates, and so on — without having to do the work yourself.