Jeff Koons has a knack for combining art and commerce. The American artist is taken seriously as a contemporary artist, and his works fetch top prices at international art auctions. The artist, renowned for its crowd-pleasing exhibitions, was the subject of a retrospective at the Guggenheim Museum in the Spanish city of Bilbao in 2015.

The oversize sculpture of a dog stood guard in front of the Guggenheim Museum in Bilbao once before, in the 1990s. The 12 meter-high "Puppy" is carpeted with flowering plants - and, back then, was a huge hit with tourists. Jeff Koons created the imposing figure as a surprise coup for the 1992 Documenta exhibition - to which he had not been invited.

Over time, Koons' works grew in proportion and became ever more spectacular. Prices skyrocketed too. Collectors include Ukrainian oligarch Victor Pinchuk and French billionaire entrepreneur Francois Pinault, who holds a majority share in Christie's auction house. Koons' "Balloon Dog" sold at a 2013 auction there for a record $58.4 million.

Critics argue whether everything Jeff Koons' production lines create should be taken seriously as art. "Ushering in Banality" is what the artist once wryly called one his works. Koons says he always wants to reach a mass audience. He certainly is successful at that: in China, his trendy sculptures are among the most-copied works of art.

In his early years at the Baltimore Institute of Art and the Chicago Art Academy, Koons was a diligent student of art history. His artworks are richly embellished with quotes from famous works from antiquity to modern times. He also likes to copy photos and use that in his sculptures - and has been sued more than once for copyright infringement.

Born on January 1, 1955, Koons sold his first painting at age 11. His father was an interior designer and owned a furniture store. As a young boy Koons became intimately acquainted with plastic decoration and backdrops there. As he told one interviewer, his later motifs are often rooted in his childhood. After completing art studies, he worked at the Museum of Modern Art (MoMa) in New York.

Everything Koons publishes as art is factory-made - in cool, impersonal perfection. He employs 128 people in his studio, which looks like a factory hall. 64 people work in the painting department and 44 make sculptures, all according to his specifications. His name is the brand and sometimes more important than the products he brings to the market - including these basketballs floating in water.

For his 1990 series "Made in Heaven," Koons used the Hungarian-Italian porn star Cicciolina (Ilona Staller) as a model and had a passionate affair with her. Their marriage made worldwide headlines in 1991. Pornographic scenes, plump silicone breasts and kitschy imagery were now part of Koons' standard repertoire.

Jeff Koons trained his sales ability early on and, as an artist, has employed it with great success. "It is, above all, about communication. And art is communication" - a credo with which he mercilessly exploits the popularity of the people he portrays in his works, including Michael Jackson. Koons also designed the album cover for Lady Gaga's 2013 album "Artpop."

Koons has regularly drawn criticism for the perceived banality of his subjects, which act like set pieces from advertisements. But museum visitors admire the radiance of works such as his "Hanging Heart," displayed in the 2008 Berlin exhibition "The Cult of the Artist."