Over on Slate, Farhad Manjoo has an article up on the convergent trends between blogs and magazines online: magazines are sometimes adopting the reverse-chronological format once definitively linked with blogs, while some blogs are aiming to look more like magazines.
While the distinction between ‘articles’ and ‘blog posts’ can probably never be expressed in a definitive way, there is something to the distinction drawn by Anna Holmes, founding editor of Jezebel:
Pieces that are primarily “reactions to something that already existed in the media or on the Internet”—the bulk of Jezebel content in its early days—are “blog posts.” But Jezebel also publishes many essays that are not riffs on outside material. These weightier, original pieces aren’t set off in any special graphical way on the site, but Holmes still thinks of them as articles, not blog posts.
It’s definitely easier to post a brief reaction to something interesting on another site (as this post does…) than it is to generate something substantive and original.