They'll probably never be officially released, unless it's a huge success. Even then, it takes a few dyas for the American companies to get it all added up and release confermed figures, so no one is going to know for a few days yet.
Its takes longer in America because the person providing the content is not the same person selling the contest. You don't buy a HBO ppv from HBO but one of the cable companies. So they have to get all the figures from the cable companies (time warner, comcast, etc) before they can give a true figure. The figure should be a lot simpler for Primetime - after all almost everyone who bought the show bought it directly from them. The Daily Mail is carrying the figure of 10,000 although that sounds very low.
They said it was ''a record breaking night for Primetime''. So we def know it was above the Froch-Kessler fight which was supposed to have been 50k.
I'd be amazed if that was anymore than an educated guess. Sky only released box office numbers if it was something they could crow about (Hatton/Mayweather) and that took a while to get out of them. 10,000 would be bad but not completely unlikely when you consider it wasn't much of a fight on paper, and the undercard was bad, and it was moved at short notice to a little known chanel that didn't do much to advertise it. I'm not saying that figure won't turn out to be correct(ish) but is probably more of a guess than them having heard anything from the primetime people in the short time form when the fight happened and when the next issue of that paper went to print which'd only have been a few hours.
If it isn't a record breaker then they should be disappointed, this is by far the biggest PPV event they have ever had..... People actually knew about the event!