If we take a closer look, the log service from blogspot, from wordpress, twitter and SharePoint log provide pretty much the same services. You find the same datamodel, similar services like publishing mechanism and similar user interface structure, like views for list of blogs or blog details.Certainly the implementation of the each solution like implementing language, hosting model and user interface are pretty much different.
Similarly, Facebook Linkedin or Yammer provide pretty much the same datamodell, functionalities and user interface structure even if implementing technologies are far from being the same.
