Yandex - Rambler Rank Checker
Rambler and Yandex are very popular in Russia and millions of users hit these search engines every month. Yandex has alexa ranking about 30, which is extremely high for a particular country. Yandex is the most popular search spider in Russia. So, getting indexed in Yandex would be very good for local traffic. Rambler is the second search engine in Russia. It is not in the world's top ten yet, but is doing a good job with millions monthly searches.
It seems like the Russian search spiders are doing the contrary of what Google does, since they're adding fancy add-ons, while Google still keeps it simple and clean.
Yandex - Russian biggest search engine
This article will help you understand Yandex search engine and the world of Non-English spiders.