LinkedIn founder Reid Hoffman
… says that data will come in two forms: explicit and implicit. Explicit data is data that users willingly give to social networks, blog posts and tweets, while implicit data is data collected in the background, like geolocation information.
There are also two types of data sets, he said: tightly held sets (passwords, credit card numbers) and open sets. He cited Google as a company focused on the open data set, since in order for its search engine to be functional, it needs website data to be publicly available and indexable by its bots so it can be delivered as search results.