Another annoying RSS feed trick
Following up my previous entry on this subject, I've run across another clever way to do partial feeds: include only the first paragraph of every entry without any indication that there's more. This works especially well if your first paragraphs are pretty much self-contained, so that they're easy to mistake for full entries.
If people haven't browsed your blog directly (perhaps because they're reading you through an aggregator), you may be able to fool them for some time. Won't they feel silly when they later realize how much they've been missing?
For bonus points, have your entries cover a variety of subjects (in separate paragraphs or sections), so people can't just read the first paragraph in your feed to get a sense of whether they want to click through to read the rest.
(In my particular case I only found out about this when I clicked through to see if an interesting looking entry had gotten any comments.)
In general, partial feeds still puzzle me for old reasons: fundamentally they're a disincentive for would-be readers to actually read your material. Some people will simply not subscribe to your syndication feeds; others will subscribe but not click through all the time. Net result: less readership. This strikes me as an odd thing to aim for.
If you are worried about overwhelming people with a stream of vastly different entries, most of which they won't be interested in, there is a simple solution: offer subset feeds. WanderingThoughts does, and I know there's at least one person who's taken advantage of it.