Rappers are increasingly promoting alcoholic drinks in which they have financial stakes, according to the Los Angeles Times.

Musicians including Pitbull, Sean “Diddy” Combs, Snoop Dogg and Ludacris are rapping about products they are selling, the article notes. In the video for Pitbull’s song “Give Me Everything,” the rapper pours a glass of Voli vodka, and mentions the brand in his song “Rain Over Me.” The bottle is prominently displayed in the video for both songs. He owns a stake in Voli, the newspaper reports.

Combs has a financial interest in Ciroc vodka, which has been featured in his videos. He has mentioned the drink many times on Twitter. In April, Snoop Dogg began promoting the fruit-flavored alcoholic drink Blast by Colt 45.

A study published last month found one in five songs that are popular with teens have explicit references to alcohol, and one-quarter of these songs mention a specific brand.

Researchers at the University of Pittsburgh analyzed 793 songs that were popular among youths between 2005 and 2007. They concluded that frequent exposure to alcohol brand names in songs may act as a type of advertising, and could encourage substance abuse among teens.