When most people think of "big data" they think of large companies with terabytes of data generated by users and machines. They also think dealing with big data is incredibly expensive and something only of use to companies. Every day we continue to increase our own personal data footprints sometimes actively and sometimes without even realizing it. Over the past couple of years the tools to inspect this data have started popping up left and right if you know what to look for.
Big companies are already collecting your data and using it to make more money. Why not collect this data (and more) and use it to your own benefit? The number of ways you can capture and benefit from your own "big data" are growing every day.