Big data has many sources. For example, every mouse click on a web site can be captured in Web log files and analyzed in order to better understand shoppers’ buying behaviors and to influence their shopping by dynamically recommending products. Social media sources such as Facebook and Twitter generate tremendous amounts of comments and tweets. This data can be captured and analyzed to understand, for example, what people think about new product introductions. Machines, such as smart meters, generate data. These meters continuously stream data about electricity, water, or gas consumption that can be shared with customers and combined with pricing plans to motivate customers to move some of their energy consumption, such as for washing clothes, to non-peak hours. There is a tremendous amount of geospatial (e.g., GPS) data, such as that created by cell phones, that can be used by applications like Four Square to help you know the locations of friends and to receive offers from nearby stores and restaurants. Image, voice, and audio data can be analyzed for applications such as facial recognition systems in security systems.