Background: 25 years old this year, software development firm made $500k in revenue so far in 2013.
Caveat: 1 million dollars revenue != 1 million dollars profit. Huge difference.
1. Have the tech skills to launch a complete web application or project that can either easily be acquired or generate revenue. If the former, aim for something viral and exciting. Think Threewords.me, which supposedly sold for 6 figures days after Mark Bao launched it. If the latter, price high and build a product for businesses or high-net-worth individuals. Assuming 30k of yearly living expenses, and not factoring in taxes (too complicated to calculate this right now), you'll need about 1,060,000 dollars. 1000 customers each paying 49 each per month over 2 years is $1,176,000.
2. Get paid at a salaried job / freelancing using said skills. Assuming you've got enough experience to do (1), you should be able to pull at least 100k. Live frugally and you can save 50k-100k from this job alone after two years.
3. Work on various iterations of (1) in your off-time from (2). Don't be afraid to sell a site on Flippa for a middling price if it doesn't seem to be growing huge. 10 sites at 5k each is still 50k.
[1] $98,500 per BTC http://www.scribd.com/doc/188644617/Bitcoin-Intrinsic-Value-...
I suppose cannabis / ecstasy / cocaine were the ones I had in my head when I made the comment.
I am just back from Nepal on vacation, where one could easily get hashish for a fraction of the price it costs here in Europe. I have reads before that drugs trafficking is significantly more efficient than any other market, arriving from producer to end consumer in way less steps than legal products.