According to DJ Walker-Morgan at MongoHQ, you don't have Big Data. You may have lots of data, but that doesn't mean Big Data. Walker-Morgan's recent post on the subject covers a number of different ideas regarding Big Data and what it all means. In particular, Walker-Morgan asks (and answers) why we keep so much data and why so much of it is of such little value.
So, maybe your data isn't Big Data, so much as "hot data," and Walker-Morgan suggests that ignoring the distinction may lead to inefficiency and misguided efforts as Big Data practices are applied where they don't necessarily belong. Walker-Morgan's full post goes into more detail on the value of Big Data and the importance of the "hot data" distinction.
And don't worry, if you determine that you're not working with Big Data after all, Chris Stuccio has you covered.