Electronic Arts and Renault announced an agreement that will enable players of The Sims 3 to download Renault's electric vehicles into the game. "This Spring, Renault's Twizy Z.E Concept car will be made available to download free of charge [...] within an Electric Vehicle Pack."
Two years ago, Ikea released a Stuff Pack for Sims 2, a year after H&M. I've also seen BP-branded windmills in the most recent SimCity Societies.
Some numbers: "Since its June 2009 launch, The Sims 3 has sold more than 4.5 million copies worldwide to date." Fans have downloaded 130 million copies of player created content that includes Sims, houses, and stories. Nearly 2 million uploads have been made to date to the Sims 3 community site, "including 20 movies each hour. The Sims 3 YouTube Channel is in the top ten most viewed sponsored channels of all time with more than 28 million video views."
-- press release, Joystiq