The magazine is owned by Richard Desmond - who also owns C5.
Gina, Dexter and Hazel have previously appeared in adverts for it, and Jackie and Charlie had an interview published in it after they entered the house.
Part of the deal with C5 BB is that the Desmond rags have first dibs on interviews with the HMs. This is a contractual obligation, and AFAIK they don't get paid for them. They seem to have taken it even further this year, with the HMs getting dragged into the mags before they enter the house...