Logging in to Facebook? Sure, you can use the social networking site’s full Web address, or you can just type www.fb.me.

The keystroke-saving shortcut is possible because the government of Montenegro makes its “country code top-level domain” — the .me suffix — available to commercial and private Internet users, for a fee. Facebook and other companies have snapped up such addresses to help draw more users to their sites — or to prevent rivals from doing so.

The sale of country codes by governments that got lucky when the endings were allocated, securing two-letter combinations that double as widely recognized words or symbols, is not new. The island nation of Tuvalu, for example, has sold its code, .tv, for more than a decade.

With a few exceptions, Internet addresses that end with country codes have failed to catch on with consumers, and .com remains the suffix of choice for marketers seeking to establish their Web credentials. But now companies that market country codes like .me, .tv and .co, for Colombia, are stepping up their efforts to sell them worldwide.

“The opportunity for us is to become the platform of choice for entrepreneurs around the world,” said Juan Diego Calle, chief executive of .CO Internet, a Miami-based company that operates the .co registry under license from the Colombian government. “To do that, we want to build massive awareness.”

One reason for the renewed push is a shortage of potential names ending with the most widely used domain suffix, .com. More than 90 million .com addresses are already in use, and the companies that sell them say few letter combinations are still available.

Another reason is a liberalization of the domain name system. The Internet Corp. for Assigned Names and Numbers, the organization that oversees Internet addresses, recently made it possible to create domain names in non-Latin alphabets, including Cyrillic and Arabic; next year, the organization wants to make it possible to create all sorts of new endings, like .paris or .shopping. Countries like Colombia and Montenegro want to get in before their country codes are lost in the crowd.

For cash-strapped governments, the sale of country code domain names is also a nice little earner. Colombia, for example, gets 25 percent of the revenue from sales of the .co name under its deal with .CO Internet. Last year, the company generated a total of $20 million from the sale of .co domains; this year, that is expected to rise to more than $30 million, Mr. Calle said.

More than 600,000 .co addresses have been sold, in more than 200 countries, he said. Only about 20,000 of those are actually from Colombia, with the most interest coming from the United States and Europe.

The company predicts that the total number of .co registrations will rise to five million within five years. Mr. Calle is hoping for a surge of interest after a high-profile marketing pitch over the weekend. During the Super Bowl, the championship game of American football, the world’s largest domain name registrar, Go Daddy, was set to highlight .co in an advertisement — featuring, as is typical of the company’s cheesy but attention-grabbing spots, “Go Daddy girls” in tight T-shirts and hot pants. In advance of the game, Go Daddy said it planned to introduce a new member of the team, a “.co girl.”

While some country codes have had a hard time attracting anything other than niche interest, analysts say the Colombian suffix may have a better chance to rival .com because the letters “co” are recognized in many languages as an abbreviation for “company” and are not merely seen as an abbreviation for the country’s name.

“As long as it doesn’t become well-known that it’s just a bastardization of the country code for Colombia, it could take off,” said Josh Bourne, managing partner of FairWinds Partners, which advises companies on the use of domain names.

Many of the names with suffixes like .co or .me are simply defensive registrations by companies that want to prevent practices like “cybersquatting” or “domain name parking” — that is, the registration of their name by a third party that essentially holds it for ransom.

To prevent that, the operators of a new top-level domain like .co are now generally required to let brand or trademark owners register their own names during a so-called sunrise period. As a result, the address apple.co, for example, automatically redirects traffic to the company’s main site, apple.com.

Some companies have been making more creative use of country code domain endings. Like Facebook, a number of well-known Web sites have used them for abbreviated addresses; these include Overstock.com, an online retailer, which recently added a shorter address, o.co, using the Colombian country code.

DoMEn, the company that operates the .me registry, has been promoting the use of .me for social media sites and bloggers, seeing it as a natural appendage for people who want to tell the world about themselves. The suffix has been employed, for example, by About.me, a start-up that lets users create personal profile pages that aggregate their presence on other social networking services; About.me was acquired by AOL in December.

Other country codes that have been adopted for similar uses include .at (Austria), .cc (Cocos Islands) and .tm (Turkmenistan.)

Yet not every country is eager to see its two-letter code adopted by marketers all over the world. France, for example, requires users of .fr to have a physical presence in the country.

“Some countries wanted to keep their domains clean and restrictive, but most of them have given up on that by now, in the search for additional revenue,” Mr. Bourne said.

While some of the companies selling country code domain names play down their affiliation with the countries that own the rights to these endings, seeing it as a barrier to wider international adoption, that is not the case for doMEn.

“It’s a good promotion for Montenegro, said Natasa Djukanovic, international sales director at DoMEn. “A lot of people who didn’t even know we existed now know where we are.”

Culled from The New York Times