The dot-com domain, which helped launch some of the most pioneering and successful internet companies, marked its 25th anniversary Monday.

'For anyone under the age of 30, they probably don't remember when the Internet wasn't in their life. It's become such an essential part of how we work, live and play,' said Mark McLaughlin, chief executive of Verisign, which administers the domain.

The first dot-com address was registered March 15, 1985, by Symbolics computer company of Cambridge, Massachusetts.

Only five other companies registered that year, and it took until 1997 to attract one million addresses, as it became the launchpad of companies like,, and, as well as spectacular failures such as fashion retail disaster and

There are now more than 80 million dot-com websites, including 11.9 million e-commerce and online business sites, 1.8 million sports-related sites, and 4.3 million entertainment websites.

In total they generate $400 billion a year, according to an independent study cited by Verisign. That figure is expected to grow to $950 billion by 2020.

The most popular words used in domain names are home (1.2 million), online (one million), and land (891,000), VeriSign said.