August 16, 2008 -- Pop icon Madonna celebrates her 50th birthday. She marks the milestone with her 8th major concert tour, Sticky and Sweet, which gets underway on August 23 at Cardiff’s Millennium Stadium, before heading to venues across Europe and North America. Madonna is ranked by Guinness World Records as the most successful female recording artist of all time, with an estimated net worth of over $400 million, and sales of over 200 million records worldwide. AVAILABLE: Graphic shows mini profile of Madonna’s career.Also caricature and story.