Is Quantified Self really new ?

Quantified Self or the Diary 2.0

Indeed, we could even say that the main idea of Quantified Self is to record data about yourself like writing in a journal.
Benjamin Franklin in the 18th century, famously tracked 13 personal virtues in a daily journal to push himself toward moral perfection. He shared this insight in his autobiography: “I was surprised to find myself so much fuller of faults than I had imagined, but I had the satisfaction of seeing them diminish.”
Besides, the idea of measuring things to highlight progress towards a goal is commonplace in large organizations. Governments tot up trade figures, hospital waiting times and exam results; companies measure their turnover, profits and inventory. 
But the use of metrics by individuals is rather less widespread. Nevertheless, we could think of the athletes who take into account many parameters like food, sleep in their preparation.
So, what is really new is Quantified Self today is the idea that everybody can store quantitative data about themselves to achieve their goals.

The innovations of the Quantified Self are based of innovation in connected objects

The smart body analyzer of Withings

Indeed, today, Quantified Self is among the hottest topics in innovation. Some of the most successful startups of the moment belong to this trend. For instance, we could think of the French startup Withings, very famous for its smart body analyzer with measures of weight, body composition, heart rate and air quality. The company has just released its new product: a watch that is as beautiful as normal watches but also able to 
monitor your activity.

The keys of Quantified Self : Big Data, Data storage, Data processing and Sensors

More precisely, the innovation in data storage and processing is crucial for Quantified Self in order to store, process and highlight information. For instance, let's say you use a wristband with an accelerometer, the amount of data you create in one day is huge. Yesterday's computers and phones could not treat it.
Besides, another aspect of the innovation in the connected objects of Quantified Self is based on the improvement in sensors. Sensors enable devices to get a variety of data like your speed, your heart rate etc. Sensors are much cheaper and smaller that before.