This issue – the rise of native ad formats – is one to watch.
Love it or hate them, banner ads provide websites a common currency for
advertisers.

 http://adage.com/article/digital/native-advertising-media-savior-custom-campaign/238010/

This article focuses on content-driven experiences on websites,
supporting what they call “Content Marketing” (geez, I hate that term! ) as
advertisers seek deeper engagement beyond the box of ad units and publishers
seek better ways to monetize (Most can’t sell more than 40% of their available
display units, anyway) at a higher rate.

What this article DOES NOT discuss is an issue that I think
is even more important: What the mobile/app centric publishing model will
unleash. With the exceptionally fast uptake of a mobile-dominant experience,
there will be a proliferation of “native” ad formats that are app/platform/media-title
specific. Examples: Promoted tweets in twitter, sponsored stories in FB. Tumblr
has them, Flipboard’s ad formats are unique. Foursquare will have them. iAd is
unique, for the most part.

Key implications:

• Media buying in the digital space may get even more
  complicated
• Long term, we may see a rise in eCPM’s
• Cross-publisher comparisons will be more difficult, due to
  the differences in the ad formats
• Measuring “engagement” will get easier
• Measuring the sales impact – always a challenge – will not
  get even more difficult

What's a brand to do in the short term? Monitor closely and do small tests and learn on your own.