I’d say WordPress.com is doing pretty well
Matt Mullenweg writes on the WordPress blog:
In August you guys created about 56k blogs, 57k users, 1.2 million posts, 188k pages, 1.3 million comments, 3.5k support requests, 196k file uploads, and around 45 million pageviews. (Not counting admin section, images, CSS, RSS feeds, etc.)
Or, just look at the stats:
Matt Craven is the former editor & publisher of The Blog Herald. Currently, Matt is the co-founder of Bryghtpath LLC, a consulting practice located in Woodbury, Minnesota. Matt's presently looking for new blogging gigs. Ping him at matt (at) bryghtpath dot com. You can follow him on Twitter.