Recently, I have seen users posting questions and then posting answers themselves afterwards. Usually, I would not be concerned about this, as it is accepted - I've even ended up doing this once after someone gave me some starting insight in a comment.
What does concern me is that some users have done this repeatedly. For example, one user has posted answers to 4 out of his top 10 questions. As well as this, the users post their answers within a short amount of time of the question (within an hour). Altogether, this gives the impression that they simply post the question-answer pair for the purpose of posting another answer. I don't want to call anyone out, but is this practice allowed/accepted?