Very often not new but existing, inaccessible data. Some estimates point to over 80% of an organisation's data remaining outside the scope of analysis.
This means poor and even bad decisions; at best case too much time being taken to unearth facts.
Before adding new data sources make sure you retrieve and analyse current, important data.
This is the first step to many a digital transformation project.
Where are CIOs and their organizations finding that value? Sometimes they’re finding it within their own organizations, in previously dark data that is brought into the light by new technologies that do a better job than ever of detecting anomalies and connecting the dots among seemingly unconnected data points. And sometimes they are finding value by tapping into new data that was not previously available to them. For example, this data includes Internet of Things (IoT) data from sensors, monitors and meters; conversations from social media; or important data from third parties about subjects such as news, securities trading or weather. IDC recently conducted a benchmark survey on big data and analytics and found that 77 percent of companies surveyed had expanded their analytics to include new data types or sources.
http://www.ibmbigdatahub.com/blog/quest-value-entering-new-era-pragmatism-data-and-analytics