Re: Thank you Facebook
I'm sure the advertising and marketing companies would like people to believe that they're all powerful and the people they advertise at are the product, but this isn't strictly true. For a start, advertising costs money. Places like Doubleclick or Facebook generally charge one fee to display the advert in the first place, and then another for the number of interactions or "conversions", which might be views ,replies, likes, retweets, favourites or clicks. They get charged even if the reply is "Get this claptrap off my timeline. I'm never going to buy it and I'll tell all my friends not to bother as well".
The money to pay for advertising comes from the companies being advertised, and ultimately from the pockets of the people (or products) being advertised to. You can analyse, data mine, aggregate and intrude until you're blue in the face, but if the "product" doesn't buy what you're trying to sell them, the subject of the advert generally doesn't stay on the market for very long. If a platform relies on advertising for most of its funding, it can have serious problems if the advertisers decide to withdraw. ITV found this a few years ago when advertising budgets were massively cut during the 2008-9 recession and a lot of their income disappeared.