Some questions can be answered in more than one dimensions. For example, a social phenomena can be explained by mathematical modelling, sociology theories, and / or political / economic theories. Should I post it on each site, stating from which dimension I expect the answer to come, or is it not a good fit for SE (violation of real questions have an answer)?
The question is different from Is cross-posting a question on multiple Stack Exchange sites permitted if the question is on-topic for each site?. People who cross-post questions often seek the same answer from larger audiences. For example, if somebody cross posted "How can I achieve this in SQL Server?" on both SO and DBA, he or she is expecting more PROGRAMMERS to see the post.
However, I would like to post some question like "Why did Clinton lose the campaign?", and I'm expecting answers from statisticians on why the polls failed, answers from political scholars on the election system of the US, and maybe also psychologist, etc. I'm not cross posting to reach a larger audience of the same group (e.g. programmers), I want answers from DIFFERENT audiences.