This article is about how artists who are creating their art by using platforms such as Tumblr or Twitter ultimately end up promoting those corporate websites and their advertisements through their work. It states,
…advertising and corporate influence present a fundamental concern for art on Tumblr and other social networks like Twitter and Facebook. Artists making work through these platforms must confront the fact that their content — the pieces they create and the media they produce — are part of an economic ecosystem oriented toward the profit of the company that owns the social web space. The advertising might not be blatantly apparently (Tumblr, for instance, doesn’t display ads on its individual user pages), but it is pervasive.
With these social media outlets having such a large user-base, it is no wonder that advertising is a major component – it will be a seen by a number of eyes!
You can check out more here.