text: The single semi-final continued to be held between 2005 and 2007; however, with 42 countries competing in the  in Helsinki, Finland, the semi-final had 28 entries competing for 10 spots in the final. Following criticism over the mainly Central and Eastern European qualifiers at the 2007 event and the poor performance of entries from Western European countries, a second semi-final was subsequently introduced for the  in Belgrade, Serbia, with all countries now competing in one of the two semi-finals, with only the host country and the "Big Four", and subsequently the "Big Five" from 2011, qualifying automatically. 10 qualification spots would be available in each of the semi-finals, and a new system to split the competing countries between the two semi-finals was introduced based on their geographic location and previous voting patterns, in an attempt to reduce the impact of bloc voting and to make the outcome less predictable.
  Entries and participants
  The contest has been used as a launching point for artists who went on to achieve worldwide fame, and several of the world's best-selling artists are counted among past Eurovision Song Contest participants and winning artists. ABBA, the  winners for Sweden, have sold an estimated 380 million albums and singles since their contest win brought them to worldwide attention, with their winning song "Waterloo" selling over five million records. Celine Dion's win for Switzerland in  helped launch her international career, particularly in the anglophone market, and she would go on to sell an estimated 200 million records worldwide. Julio Iglesias was relatively unknown when he represented Spain in  and placed fourth, but worldwide success followed his Eurovision appearance, with an estimated 100 million records sold during his career. Australian-British singer Olivia Newton-John represented the United Kingdom in 1974, placing fourth behind ABBA, but went on to sell an estimated 100 million records, win four Grammy Awards, and star in the critically and commercially successful musical film Grease.