http://www.boxingnewsonline.net/BNTV.asp?VideoID=217
Warren lets slip how many viewers / subscribers Boxnation have. Listen from 10:45 onwards. He seems to be suggesting Boxnation have 200,000 subscribers which is twice he figure the channel needed to break even. He did also mention at around the 6:00 mark that Boxnation are 100% ahead of their target for subscribers.
The interview is pretty interesting, especially the first 5 minutes when he discloses what SKY used to pay him.