Ok, I’ve finally given in, and have started blogging. For several years now, it has become clear that mailing list posts alone were no longer working. Just as with Usenet posts before, the readership has split up (into specialist sublists, IRC channels, blogs, etc.).
What has tipped the balance at last were two things: archiving and interests spanning more than a single language community. In the past, it was worth writing longer answers to mailing list threads, because the search engines would find them in the archives.
For Haskell-related lists, that has been working less and less (some years ago, a mis-edited
robots.txt file prevented web spiders from indexing the main list archives, and these days, there are several archives for each list, dividing any Google rankings between them; hint to Google: the main list archive is listed in each list posting’s header).
And though Haskellers tend to be interested in other languages, posting only to Haskell lists misses the other language’s community, and cross-posting isn’t all that nice, either.