What are the reasons why companies decide to develop their corporate site using SharePoint?

Two main reasons: collaboration and managing knowledge and content.

Experts better connected

Microsoft SharePoint is a collaboration platform that brings people and content together, allowing employees to share ideas, identify common goals and discover answers. SharePoint creates a virtual office where content is shared and developed through participation. Sharing knowledge results in business success by enabling employees to locate and tap into the expertise, knowledge and information that others across the organisation have.

Information available anywhere anytime

When it comes to business projects, getting the desired result means getting the most out of your team. However, when the information the team needs to perform is scattered across your company (on individual computer hard-drives, USB pens etc) it is more difficult for them to produce results quickly and effectively. More than 50% of staff costs are now spent on employees performing information work and ineffective searches for information can cost a company up to 10% of its salary expenses (NetworkWorld 2006).
SharePoint manages your content allowing you to: store, organise and locate documents; ensure the consistency of documents and avoid multiple versions; protect documents from unauthorised access or use; and ensure consistent business processes (workflows) for how documents are handled. SharePoint has a ‘search’ feature enabling you to find the relevant information you require across SharePoint quickly and effectively.

Workflows specifically help people to collaborate on documents, improving efficiency and productivity by managing and tracking the tasks and steps involved in business processes such as project approval or document review, enabling the people who perform these tasks to concentrate on performing the work itself.