This question may belong to <Another site>, consider migrating - feature request
I often see on SO questions that by the topic belong to one of the SE sites (mostly it's wordpress related questions, so i will use wordpress as an example in this text).
Let's imagine we checking new questions on SO, just to check if they are on topic, well formated, not duplicated, and all that stuff. And we found one Wordpress question. First we think to flag it and hope that a moderator will migrate it to the wordpress SE, but those question always have some other tags and those are related to SO. And while you are considering what to do with this question, flag it or leave it here, some users start to respond to it, and mostly they solve the question. Looks like everything worked out ok, but for some reason we have all the SE sites, and people there wanting to create their own very specific community, and we just stealing users from them. It's mostly not our fault, the user who asked the question didn't know that there is a specific community about wordpress.
My point, and proposal, is to create some tool which, when a user creates a new question, checks if he used some tags/words in the title that are the main topic of an SE site. The same way we show the Related Questions box, we can show some box where we say something like "Hey you are trying to ask a Wordpress question here, but we have a Wordpress SE site, specifically created for you; check this box and we will automatically send this question there".
This way we will give the user the oportunity to choose if he considers his question more related to Wordpress, or to some topic which belongs specifically to SO.