"If you are not paying for it, you are the product being sold". That holds true for many today's digital services. There is no shortage for free services that are willing to take you as one of their products.
What this is generally thought to mean is that your data is the product that these companies are selling. Your preferences and usage patterns are worth something for the right party. While that doesn't sound too bad, considering the service you get in return and perhaps an appropriate ad for a product you probably are interested in as a bonus it's unfortunately the whole truth.
The most valuable asset in this productized you is actually your behaviour! Yes, you are not only being profiled, but the aim is to change your behaviour. Sure, commercial entities only want to change you into their loyal customer, but imagine the potential of this subtle change in the hands of some irresponsible political entity. How they could affect the general opinion in their favour and make them seem like the better option.
Good thing this hasn't happened yet...