as far as im aware sky go doesnt work on rooted devices which that one looks like it is. Can probably get it through other means like the xbmc/kodi app on there but i never had much luck with that personally, seems others managed it though.
i've got that exact box and it's highly likely it's also rooted so sky go won't work. the "jailbroken" bit on the advert is likely the seller's way of saying it's rooted as well.
but then the sports devil plugin for kodi will get you pretty much any sport you want
anyway, if you want the box for £33.25 and don't mind ordering it from china, you can get it here