beta-reading for fun and completely no profit

[arcanetrivia]

Do you have absolutely all of your work beta-read? If not, when do you not?

This question comes about because I noticed that alisanne has all of her drabbles betaed (by sevfan), and that seems unusual. I've seen a number of other people say that they never bother to have drabbles betaed, while they do most/all of their other stuff. I suppose with a piece that short she's just having someone check it quick for errors of mass stupid, but still.

I never have my drabbles betaed. In fact, a lot of my stuff (as though there were a lot! ha!) has never been passed through a beta because I regarded it as highly non-serious, just written as a lark, or sometimes literally as a joke (e.g. "Potion-Induced Comma"). I certainly don't beta the stuff I write about silly summaries, which often is long enough to get a "drabble" (<200 words) or "ficlet" (200-1000 words) tag. Not that crack/humour can't be done "for serious", just that that wasn't what I thought I was doing.

So. What are the factors that would cause you to pass up having something betaed, if anything? Just curious.