About 15-20 years ago the em dash became popular in the Russian web-design community because, surprisingly, it is the proper character to use. Using "-" was a sign of low-quality work. I remember I even wrote a small app in C#, so I could have it on the screen, click a button, and get "—", "«" or "»" in the clipboard ("«" and "»" also mattered, because " is not really a legitimate character in Russian typography).