Mention "native advertising" to a media buyer these days, and he or she will ask what exactly you mean by it. Advertorials? Promoted Tweets? Search ads? Sponsored content?
The term has become industry shorthand for any ad product that isn't a banner and looks like the content around it, or anything the Interactive Advertising Bureau hasn't standardized. It's the ad industry's latest salespitch, and not without reason. Banner ads are broken, so marketers and ad-sellers alike have a good reason to at least attempt to move beyond them.
Publishers have created some really interesting innovations in the name of "native" advertising, but can we agree that we should all stop calling them "native?"