A realization: planet aggregators have a natural size limit
For reasons that are too complicated to fit within the margins of this entry, I've recently been dipping into reading some planet blog aggregators. The experience has sparked a realization: planet aggregators have a natural, intrinsic size limit.
The example that crystallized this for me was considering the possible growth of Planet DCS. Between professors and graduate students, there are at least three hundred people here who could have blogs aggregated onto Planet DCS. If we assume that 200 of them take seriously the exhortations to blog and that each of them writes just one post every four days (and that the postings are evenly distributed in time), the planet will get 50 new entries a day. Not only is that a lot of entries to read a day, but it means that the planet's web page rolls over awfully fast; if you don't keep up, you miss things.
This is what I mean by planets having an intrinsic size limit. Because of their lack of history, you can only add so many people who are posting so frequently to a planet before it starts being unreadable. If you add enough people and they blog frequently enough, what you wind up with is not an aggregator but a random patchwork view of some recent activity, as the planet rolls over entirely several times a day.
This is kind of unfortunate; it means that if you have a fairly general planet that a lot of people could be aggregated to, its very success could kill it as a useful resource.
(Or the planet operator would be in the uncomfortable position of having to tell people that they couldn't be aggregated on a popular place merely because they hadn't got there early enough.)