My view, as an outsider who has never raised money for a startup, but that watches the industry with a level of professional interest is that media startups aren't an obvious sell for investors. Why? Content. They need users and content to sell. So, Flickr is obvious, but random new content based startup, not so much.
With tech startups, it's different - there's potential for value add to the bigger fish. An obvious sell-by date.