Overstock.com today began using the domain O.co, directing consumers who type in O.co to the web-only retailer’s e-commerce site, Overstock.com. The company says the new name represents a step in Overstock’s effort to brand itself around the letter O.

Overstock, No. 28 in Internet Retailer’s Top 500 Guide, paid $350,000 for the domain name in July on the first day that .co domain names became available from the .CO Internet S.A.S. registry operator.  Organizations and individuals have bought about 600,000 .co domain names. Social network site Twitter, for instance, has bought T.co, while GoDaddy, a web hosting domain registry, now owns X.co. According to the client list on .CO Internet’s web site, Overstock.com appears to be the only e-commerce company using a one-letter .co domain.

Overstock says the O.co name highlights the company’s evolution into a globally recognized brand. The company ships to 94 consumers in countries through a shipping and logistics vendor but all Overstock business operations remain in the United States.

“Over the 11 years we’ve been in business we’ve evolved into a savings engine for shoppers. We have become O.co,” says Patrick Byrne, chairman and CEO of Overstock.com. The company recorded $6.6 million in international sales for the nine months ending Sept. 30. It recorded more than $741.0 million in total revenue for the same time period.

The company already focuses its advertising efforts around the letter O and also calls its loyalty program Club O.

Last year, it launched Eziba.com, a daily-deal site that focuses on products for the home. At that time, company president Jonathon Johnson said the company selected Eziba over the Overstock name in part because some product manufacturers expressed concern about having their products for sale on a site called Overstock.com, reluctant to have their brands associated with a word that implies discounting. “Eziba helps us with suppliers who were eager to sell through us but not be on the Overstock site,” Johnson says. ”As good as we think we are there is still some stigma about selling on a site called Overstock.com.”.