The YouTube shooter was reportedly angry that she made as little as 10 cents on some of her videos.
Nasim Aghdam, 39, opened fire at the YouTube headquarters in San Bruno, Calif., Tuesday afternoon, injuring three people before turning the gun on herself.
Aghdam's videos were watched by nine million people, but she found out that getting famous on YouTube doesn't guarantee a big payout.
"My revenue for 300,000 views is $0.10????" she wrote on her website.
Aghdam's family emigrated from Iran to the U.S. in 1996. In Iran, she was a big social media star under the name "Green Nasim," but she grew disillusioned with life in America.
"If you are superficial, you will think it is heaven here," she said. "But if you enter the system, you will see that it is worse than Iran."
Aghdam, a vegan who was passionate about fitness and animal rights, was photographed at a PETA protest in San Diego in 2009. In the image, she held a fake dagger and painted blood on her face.
Some viewers of her eccentric videos questioned her sanity, but she responded, "I don't have any special mental or physical disease. But I live on a planet filled with disease ... perversions and injustices."
Aghdam's father spoke to reporters outside his home Wednesday.
"I apologize," Ismail Aghdam told KGO. "All the U.S. people, all the humans, I apologize. I am sorry. I can't believe it."
He also released a statement on behalf of the family saying they were in "absolute shock and can't make sense of what has happened."
"Although no words can describe our deep pain for this tragedy, our family would like to express their utmost regret, sorrow for what happened to innocent victims. Our thoughts and prayers are with them and their families," it said.