Business.com

Business.com made a record in 1999 when eCompanies, an Internet incubator, paid $7.5 million for the Web domain name, putting it on the list of the highest domain name transactions in history. Business.com is backed by venture capital firms Benchmark Capital and Institutional Venture Partners, as well as media giants Reed Business Information and McGraw-Hill. However, no one could have predicted that this domain would be worth 47 times more in just 8 years.

After Dow Jones and The New York Times attempted to purchase Business.com in the years after 1999, the domain's value skyrocketed. R.H. Donnelley, which publishes print and online phone directories, announced the acquisition of Business.com for $345 million in cash plus additional delayed payments. However, the buyer was unlucky in this specific domain name sale. Only two years after purchasing the domain, the third-largest print and online Yellow Pages publisher in the United States entered bankruptcy.

Price: $345 million