In investment, it is the business question of determining a company's intrinsic value. A security should be bought with the knowledge that the characteristics of the products, management capabilities, and target markets support sustained growth over a long period of time. They are not always right. Speaking of the Internet, any emerging markets will show signs of strong volatility at the beginning when it is not yet clear what the business fundamentals are and where the revenues will come from.
Many people speculate for short-term profits.
Personally, I see strong growth in Internet-based systems and services over long term. For parallels, just look at the Microsoft trajectory since the MS-DOS days. Diskeeper Get Max System Performance.