Fun fact: when I first wanted to ask a programming question on Stack Exchange, I signed up for Programmers, assuming that was the right place. I posted my question (10k+ on programmers only), and then figured out it wasn't the right place. 6 minutes later, I reposted my question on Stack Overflow and deleted it from Programmer's.
Fast forward a year. I wanted to ask an Excel question only to end up absolutely boggled by where I should be posting it because there is considerable overlap between SO and SU on the issue.
Multiple sites can be confusing to new people (and even semi-experienced ones).
On Stack Overflow in Japanese questions that would be on Super User are welcomed and get good reception and good answers. It seems to be working well enough, and the Japanese version of me is hopefully grateful that they don't have questions about where they're supposed to be asking, and can focus on the quality of their question instead.
