Change.org just got a $30 million investment to expand petitions into real social movements

Change.org is getting some major support from tech billionaires to create real social movements.

LinkedIn co-founder Reid Hoffman is leading a $30 million funding round for the site in what he said in a post on LinkedIn was his largest personal impact investment to date.

Bill Gates and Y Combinator's Sam Altman are also investing in Change.org in this round, Change.org CEO Ben Rattray said in a blog post.

"As a society, we should be doing everything we can to build powerful, easy-to-use civic spaces where upstarts and idealists can effectively challenge entrenched interests. Where people believe their participation makes a real difference. Where every day, in transparent fashion, individual citizens can join forces in highly democratic efforts to make the world a better place," Hoffman wrote in his LinkedIn post. "That's why I'm making this investment in Change.org."

The site, founded in 2007, lets users create and sign petitions and advocate for causes ranging from clemency for people convicted of nonviolent offenses to developing a new constitution in Mexico City — two campaigns Hoffman called out in his post.

Change.org has raised $42 million in its 10-year history, including a $25 million Series C funding round in 2014. Gates, Hoffman, and Altman all invested in that round, as did Arianna Huffington, Ashton Kutcher, Twitter's Ev Williams, Richard Branson, and Nas.

The $30 million investment this time around will be used to turn Change.org's monopoly on online petitions into support for real social and political movements and to expand the site's crowdfunding and monthly membership features.

Crisis Text Line founder Nancy Lublin, LinkedIn co-founder Allen Blue, InnerSpace and Flixster founder Joe Greenstein and entrepreneur Sara Imbach will serve on Change.org's board.

Hoffman said he will donate any increase in equity value that he gains from this investment to nonprofits, including Change.org's own charitable foundation.

"Our aim in the years ahead will be to design the type of scalable, sustainable technology that will channel this energy into ever-more effective, constructive action," Rattray wrote. "In doing so, we hope to help create the world most people want — a world in which no one is powerless, and where the policies of governments and practices of business reflect the public good rather than private interests."