Nicki Minaj believes she'll be a billionaire by 2025 through ''investments and selling companies I've started''. The 32-year-old rapper - who has released three albums, three fragrances and is set to star in the upcoming film Barbershop 3 - insists she is a very smart business woman and is building an empire. Asked how she plans to make her first billion, Minaj, who made $14 million last year, said: ''Not from my albums - on my god. People don't make money from albums. But we're talking about business, investments and selling companies I've started.'' Minaj also admits she is competitive when it comes to money. She said: ''Women are uncomfortable talking about money. It probably stems from our mothers, who passed it down to us - generation to generation - to not speak about it. We weren't in that role a long time ago. I know it's taboo to discuss it at work. Technically, you shouldn't but you need to know what people around you are making. Otherwise, you're not going to know what you're worth. ''I've always been pretty competitive in terms of my pay.'' The Super Bass singer is also ''tough'' on her employees and herself, but is motivated by the need to feel more secure. She told the July issue of Cosmopolitan magazine: ''I don't really believe in excuses - even with myself. People tell me I'm a workaholic. ''I wasn't born into a rich family. I always feel like it could all be taken away from me tomorrow. God forbid. But it's not guaranteed, so you might as well go as hard as you can.''..