These type of ads are known as "advertorials". They are not new (read: http://en.wikipedia.org/wiki/Advertorial). They are new in digital realm. In print magazines/newspapers, we are also used to the concept of "advertising supplement". We are in early days of "advertorials" in digital world and they should mature over the time. They are ought to become better.
Typically advertorials use a distinct font and possibly rules (as in borders, lines) to differentiate itself from straight editorial. Sure, we know the difference. And yes, it actually does feel different, and yes that matters.
