It's all based on strategy, business knowledge and some luck ;)
It's actually simple real estate trick... Buy the old, fix them and make them attractive and better looking and sell with a lot higher price. For instance the domain bird-cage.com was bought for a mere $1,800 in 2005. After a great redesign and two years later, the site was sold for $173,000 to a bird cage vendor.
Feel free to read more on this link.
