Andrew and I have been talking about what makes a good technical community Planet. Here are some thoughts about what the best planets have, keeping in mind that it is probably not possible to achieve this by any other means than luck:
Critical mass
This seems to be somewhere around about the twenty or thirty writers mark, just in order to achieve content that changes regularly. This seems to be the major failing of Planet Twisted. You might get regular content from as few as three or four people, but it will get same-y.
Community leaders
It’s most interesting to see actual decision making discussion happening through entries themselves, but after the fact analysis is nearly as good. But you won’t see any of this if you don’t have key decision makers or at least opinion makers blogging about decisions and direction. I see this as one of the big advantages Planet Debian and Planet GNOME have over Planet Ubuntu. My primary interest here is for interesting reading, but this has a bonus side-effect of greater community transparency: a lot more relative outsiders scan Planets now than scan development mailing lists.
Expert writers
It’s useful to have a significant set of regular writers who write in some area of their personal expertise, be it user interface design, translation, programming or cat herding. This decreases the sense that you’re reading uninformed and predictable reactions to technical decisions and increases the chance that you’ll learn something new by reading.
It adds a bit of spice to have some of these writing about project irrelevant expertise (climate change, workout programs, photography techniques) because it increases the “smart people who I’d love to go to dinner with” vibe. It can be overdone though: while it’s likely that your writers are the best there is to offer on technical subject X, it’s less likely that they make as universally interesting reading on their other interests, because it’s less likely that they’re the people worth listening to and it’s less likely that their interests overlap with those of the readers. Sometimes you get lucky and sometimes you don’t.
‘Journal’ blogs are hard to pull off on masse: it’s both a tempting format and a difficult one to make work for readers who have no prior interest in the writer’s personal life (ie, everyone who isn’t friends or family). These blogs are much like outside interest ones: considerable payoff in community spirit if they work, risking uninteresting reading in many cases.
A Planet community
The best Planets are full of people who actually read the Planet and let it inspire their entries. I also find that planets from a focused technical community have an advantage over planets from a user or random community because they’re more likely to make for coherent reading with common threads.
Inter-entry conversations
Once you have a Planet community, the best Planets start having extended inter-blog discussions during which you can see opinions being formed, revised and finalised. This is the Planet zenith.
So-called memes (standardised entries based on quiz results or a common entry template, which tend to be quick and fun to write and therefore highly contagious), as in all other blogs, generally are the most common and most boring kind of inter-entry conversation. There’s not a lot to gain as a reader from knowing that someone is more like Bilbo than they are like Sauron or which countries they’ve visited unless this is used as a platform to make some kind of debatable point (almost every opinion that’s actually interesting is debatable) or to tell a story, and people do this too seldom.