They're like junk food. Each one is tiny, scrumptious, and generally useless if one hopes to do something meaningful with writing. As a whole, they're addictive good fun, possibly for the whole family. For some people it's a good break from 'real' writing. For others, they're too small to be worth cranking up ye olde literary digestive system.
I've sucked in two other people from a smallish writing community, and we keep adding to an increasingly silly story about a tree. One of them has started a separate one about a forsaken holy cow, and I have ideas in mind for that, too. :)
I blame John Scalzi for all this. His technical difficulties on Whatever, followed by its full shutdown until mid-September, has left me with a social void. I miss reading his posts every day, but moreso I miss the peanut gallery of commenters. There was Patrick M.'s attempts to grok politics via football, and Jim Wright's salmon fishing in Alaska. There was the group hounding of our fearless leader to visit the Creation Museum like he'd promised (and we'd paid for!).
In some ways it's like having a roleplaying game go on hiatus. We're all left hanging mid-story, but we also know that the fun will come back someday. We just have to find other ways to fill the void in the meantime.