In BB7, Dawn Blake became the first contestant to be ejected for having contact with the outside world. Dawn organized a special code with her family: if there was any bad press regarding her, then their family would tell Big Brother that her sister was ill. Dawn received this message and informed the other housemates of this code.
Series 1-6 of Big Brother (2000-2005), including the four series of Celebrity Big Brother in between, were some of the very few programs on mainstream British terrestrial television that were broadcast in the old 4:3 aspect ratio as opposed to the more common 16:9 wide-screen format. (Except the Big Brother Panto, which was in wide-screen). The reason for this is unclear, but was believed to be because of the size of some of the hidden cameras. However, from Big Brother 7 (2006) the aspect ratio has been switched in favor of the 16:9 format, with Big Brother, and all of its sister shows, broadcasting in wide-screen.
In total, 21 housemates have voluntarily left the house. 2 housemates have left the house due to medical reasons; in series 11, Keeley Johnson left the house after she broke her ankle during the 'Save and Replace' task, and in series 15, Kimberly Kisselovich left the house due to a mystery illness, which was later revealed to be an ectopic pregnancy. In series 13, Conor McIntyre left the house with £50,000 (half the prize money) as part of the 'White Room' twist.
The action from within the house is streamed live over the Internet for a one-off fee subscription that lasts until the end of a series. Since the second series Channel 4's sister station E4 has also carried live pictures and audio from the Big Brother house. However the stream had a delay of 15 minutes so that audio and/or pictures can be edited out to comply with TV regulations.
Following the end of Big Brother 7, 156 house-mates have inhabited the house (not including the 8 participants in Teen Big Brother). 33 of those were celebrities, including Chantelle Houghton, the non-celebrity contestant in Celebrity Big Brother (2001) series 4.
Each year Big Brother is a ratings winner for Channel 4. The final of Big Brother 3 on 27 July 2002 was watched by 10 million viewers, the highest ever ratings for a non-film on the channel, and BB3 as a whole averaged almost 6 million viewers. Big Brother 6 had an average of 4.4 million, the poorest in the show's history. BB7 was ahead of it, averaging 4.7 million viewers. However the finale of Big Brother 7 at its peak reached 8.2 million viewers.
The only eight housemates in the history of Big Brother to be thrown out for rule-breaking are Nicholas Bateman in series 1, Kitten Pinder and Emma Greenwood in series 5, Dawn Blake in series 7, Emily Parr in series 8, Alexandra De-Gale and Dennis McHugh in series 9, and Daley Ojuederie in series 14.
Series 7 was the first series to allow a random member of the public to enter the house. 100 golden tickets were placed in Kit-Kat chocolate bars, granting the finder a chance to enter the Big Brother house. Of those tickets, 58 were found before the deadline, but two people decided not to put themselves forward for the show, three dropped out, and 19 did not pass the required background checks, leaving a total of 34. The competition began at 10:30pm on May 18, 2006, the launch date of Big Brother. Susie Verrico became the "Golden Housemate" after being randomly selected in a Bingo style machine, as each ticket-holder were randomly given numbers to wear as hats and armbands on the day.
Every single housemate to become the first to be evicted in each series has been female: Sada Wilkington in series 1, Penny Ellis in series 2, Lynne Moncrieff in series 3, Anouska Golebiewski in series 4, Vanessa Nimmo in series 5, Mary O'Leary in series 6, Bonnie Holt in series 7, Shabnam Paryani in series 8, Stephanie McMichael in series 9, Beinazir Lasharie in series 10, Rachael White in series 11, Tashie Jackson in series 12, Victoria Eisermann in series 13, Sallie Axl in series 14, and Tamara Stewart-Wood in series 15.