According to someone I used to work with, and now is employed to investigate sites that spread viruses by one of the major anti-virus companies, VK.com is a large "community site".
What we see (the rugbyonthesofa bit) is only a small part of it. It is basically like Facebook and Youtube rolled into one. In fact it has co-agreements with Facebook such that posts on either site will appear on the social media part of the other.
The streaming side, we know about, looks to be a "loss leader" to attract users to the other parts of the site, where there is a lot of advertising, and it appears that signing-up results in you receiving ads via email. (Most are in Russian)
It has many legal streaming agreements with Russian organisations that have the Russian rights to Western films, music and TV, and these include the company that has the rights to beIN sports coverage. It is faster at removing user-posted illegal content than Youtube is, but because of the agreements it has in place almost all illegally uploaded content will be replaced by the same content from a legal source (legal as in "Legal in Russia")
The site is legitimate in that it does not spread viruses, and, as long as you don't venture onto other parts of the domain you will be safe. (There are a lot of subsections that could, at best be regarded as pornographic, drug related or just plain criminal)
Like many such sites it was set up by a computer sciences graduate, fresh out of University, originally with Israeli backing, however it is now controlled by Russian government backed organisations, many think because the site was used by many Russian dissidents, and the Kremlin wanted to find out who they were.