Cloud Computing for lay man

Let’s ponder on Cloud Computing try to understand if it for everyone etc.
Start with a definition from Wikipedia, Cloud Computing a style of computing in which dynamically scalable and often virtualized resources are provided as a service over the Internet. Users need not have knowledge of, expertise in, or control over the technology infrastructure ‘in the cloud’ that supports them. The concept include infrastructure as a service, platform as a service and software as a service as well as Web 2.0 and other recent technology trends which have the common theme of dependence on the Internet for satisfying the computing needs of the users. Examples of software service vendors include Salesforce.com and Google Apps which provide common business applications online that are accessed from a web browser, while the software and data are stored on the servers of the providers.
The majority of cloud computing infrastructure consists of services delivered through data centers and built on servers with different levels of virtualization technologies. These services are accessible from anywhere that has access to the internet & required authority. The cloud appears as a single point of access for all the computing needs of given consumers or groups. Commercial offerings need to meet the quality of service requirements of customers and typically offer service level agreements. Open standards are critical to the growth of cloud computing and open source software has provided the foundation for many cloud computing implementations as the fees are affordable in terms of licensing etc for end users.
In Cloud Computing customers generally do not own the infrastructure, they merely access or rent, so that they can avoid capital expenditure and consume resources as a service, paying for only what they use. Many cloud-computing offerings have adopted the utility computing model, which is analogous to how traditional utilities like electricity are consumed, while others are billed on a subscription basis. We just have two models 1) utility computing 2) billed on a subscription model.
Sharing computing power among multiple tenants can improve utilization rates, as servers are not left idle, which can reduce costs significantly while increasing the speed of application development. Also it can include many advantages as time zone utilization etc to spared the costs over the globe.
“Cloud computing users can avoid initial investments on hardware, software and services, rather paying a provider only for what they use. Consumption is billed on a utility (e.g. resources consumed, like electricity) or subscription (e.g. time based, like a newspaper) basis with little or no upfront cost. Other benefits of this time sharing style approach are low barriers to entry, shared infrastructure and costs, low management overhead and immediate access to a broad range of applications. Users can generally terminate the contract at any time (thereby avoiding return on investment risk and uncertainty) and the services are often covered by service level agreements with financial penalties. This is for a generic user now in next write up I will put up Cloud computing for business delegates in a bit techy tone. Do share your view with me.