One of the great aspects of cloud computing, or software-as-a-service, is that it scales efficiently (making it a good strategy for operating in tough financial times). Paying per mailbox per month for email hosting, for instance, scales down gracefully when your summer interns go back to school. But if you had an Internal Exchange server you would have had to purchase Exchange Client Access Licenses (CALs) for those interns to have mailboxes, CALs that now sit idle for 9 months, money wasted.
With the introduction of Creative Suite 5.5, Adobe has introduced Subscription Licensing, whereby you can pay per month for the software you need, rather than buying the licenses outright. This makes a lot of sense for creative companies who might have some number of permanent creatives on staff and bring in contractors and freelancers on a project basis. Bringing in a freelancer for a 3-month project? Not sure you’ll still have enough work in a couple of months to keep that new designer you just hired? Don’t shell out $1,700 for CS5.5 Design Premium, “rent” it instead for $139/month.