External collaboration has never been easier with SharePoint Online. Every end-user can store documents on OneDrive for Business and share these document with external users. SharePoint Online has the Project site template that contains valuable features to collaborate in projects with customers. These features are a newsfeed, OneNote integration, a document library and a task list with a timeline to present important tasks in a clear overview. It doesn't stop here! Microsoft acquired Yammer in 2012 and Yammer is shifting as the Social tool for SharePoint. Through its integration with SharePoint Online, you can easily start discussions about the projects content. The combination of SharePoint Online and Yammer proves to be the perfect solution for Extranet scenarios.