Fair enough, but being on HN, I sincerely doubt you are a typical russian internet user. Most Russian people I met only used vkontakte, and only used facebook

Fair enough, but being on HN, I sincerely doubt you are a typical russian internet user. Most Russian people I met only used vkontakte, and only used facebook because they either had a company to promote internationally, or studied abroad, somehow didn't end up in a typical russians-abroad clique, and wanted facebook "on the side" to keep in touch with their international friends (who are obviously not gonna be on vkontakte).