They are your Sky card viewing number, albeit changed with a calculation (presumably only known to Sky). Apparently the numbers are part of Sky’s attempt to try and stamp out piracy of its channels on the internet, and to see which pubs are using a private subscription and not a publican subscription... by displaying the viewing card number on the screen or feed, Sky can see which Sky card is being used for sharing the programme content over the streaming websites, and deactivate that card. The same method can be used by Sky, in conjunction with “mystery Drinkers” to see which pubs are using a domestic subscription and not the more expensive Pub subscription.
http://www.uksatellit...bove-sky-sports-logo/