There’s been a lot of coverage over the last few years of the investments made in two media companies in particular, BuzzFeed (currently valued around $850 million) and Vox Media (valued around $400 million). These valuations are not—cannot be—based on a content-plus-ads model. (Neither is Gawker’s for that matter.) But they do reflect these sites’ promise to advertisers, both as a platform for ads and a creator of them. More generally, they are a product of four current trends in online advertising:

Native advertising (or “custom content”), in which paid material closely resembles editorial content.
Custom social media content that’s deployed directly on Twitter, Facebook, or other networks rather than on a site or blog. (Vox Media, for example, has played up its social media engagement.)
The growing importance and dominance of mobile, whose varying formats and usage patterns are less compatible with big, bright banner ads.
End-to-end advertising providers, or companies like BuzzFeed that offer clients a one-stop shop for production of the advertising content itself, the platforms on which it’s to be deployed, and placement on specific sites.