What are some alternatives?
Reddit - Reddit gives you the best of the internet in one place. Get a constantly updating feed of breaking news, fun stories, pics, memes, and videos just for you.
Nativo - Nativo is an advertising technology platform for brand advertisers and publishers to scale, automate, and measure native ads
Digg - Digg delivers the most interesting and talked-about stories on the Web right now.
Pixfuture - Pixfuture is a self serve advertisement platform for advertisers and publishers.
Zemanta - Zemanta is an online content and links suggesting platform that provides a plugin to the bloggers, publishers and other types of content creators.
StackAdapt - Native advertising demand side platform.