This question already has an answer here:
On this page, it is stated that posts enter community wiki mode when it has been edited six times by the original owner.
Why is that? I often edit posts for small, merely cosmetic reasons and do not want them to be turned wiki. I'm well aware of the automatic preview, but even after carefully considering an edit, I often (multiple times per post) notice something a few minutes or hours later.
The number stated in above link may not be actually correct. The current value (and implementation details) seem to be unknown. If the actual number were, say, 20, I would not mind, since a value that high ought not to cause any trouble. On the other hand, if it were 5, I definitely would.
Edit: It seems a main concern is that users would be able to bump often. In this case, there are some rather easy ways to prevent gambling in the comments to Ian's post, so I don't this this should be an issue.