It’s only taken them a few years, but it appears that banks and credit card companies are finally realizing that maybe (just maybe) it would be smart to promote their disposable credit card number offerings.

MBNA Corp. has offered this substitute card number – which typically has the same number of digits as a regular credit-card number – free to its customers for a couple of years. And both Citigroup and Morgan Stanley’s Discover Financial Services division are planning on enhancing features on similar products later this year.

At the same time, a greater amount of money is being spent online each year, increasing the potential for fraud.

By 2007, about $104.5 billion – representing more than 5 percent of total U.S. retail sales – will be spent online on items such as clothes and electronics, according to JupiterResearch, a division of Jupitermedia Corp. in Darien, Conn.

By offering virtual account numbers, financial services companies are looking out for their bottom line. They’re hoping that these tools will give more consumers the confidence to shop on the Web, potentially increasing credit-card revenue.

Also, card issuers are betting that less online fraud means less money coming out of their own pockets to pay for unauthorized purchases. (Cardholders are typically not responsible for fraudulent transactions.)

More here.