Aside from winning the lottery (either literally or figuratively), the fastest ways are going to include consistently investing in the stock market, or investing in your own business. If you can become an entrepreneur and grow your business, you can make enormous amounts of money relatively quickly. I recommend a cleaning business, a coin car wash, or real estate (including flipping houses); the first two are relatively easy and straightforward, and the third is a well known business model.
Dollars or users? And for yourself or your project/company?