Inbox interactive: Mexico's Tralix has an answer for your marketing questions--just open your e-mail.

Forget focus groups, those expensive gatherings of real people around a table to react to new products or campaigns. When Mexico's Grupo Editorial Expansion wanted to choose a cover image for its sassy magazine Quo last year, the publisher went virtual. It simply polled potential readers through e-mail.

A panel of 750 people who matched the magazine's reader demographics viewed two cover images via e-mail, one with a sexy woman and the other with a clownish man. They selected their favorite by clicking on a box embedded in the e-mail. Panelists never had to click a link to enter a Web site, and the magazine publisher had access to the results the second they made their choices. (The woman won.)

The technology behind this survey came from Tralix, a young Mexico City company with plans to go global. Some say Tralix's technology is revolutionizing e-mail marketing, which has become an essential way of communicating with customers because it's quick and cheap.

Mexican bank Banamex began using Tralix technology last year when it launched its first e-mail marketing campaign, says Juan Emilio Simon, head of marketing intelligence for Mexico's largest bank. Since then, more than 600,000 people have signed up to receive promotional e-mails from the bank.

The bank targets its campaigns to reflect customer preferences and demographics. Last year, young music-lovers received a chance to win tickets to see the U.K. rock band Coldplay while middle-aged married couples were offered the chance to win airline tickets from Mexicana. As each user opens the promotion, Tralix technology lets Simon's team see which customers have chosen to enter the contest.

"We can see immediately if it's working or not, and we can close it if we need to," Simon says. The response rate depends on the campaign but can be as high as 20%, and the average is more than 10%, he says. Simon figures that with a mail-out or a newspaper insert, the response rate would be around 3%.

E-mail recipients do not have to click through to a Web site to participate. That's important, says Tralix CEO Luis Antonio Ascencio, because people click through just 8% of the time. "A marketer's goal at the end of the day is not just to send a message that's read," Ascencio says. "There's also a need to stimulate the audience to perform a certain behavior--to answer a survey or to make a purchase."

The advantage of e-mail marketing is that, unlike television or print advertising, you can easily tailor the message for the individual customer, says Sridhar Balasubramanian, assistant professor of marketing at the Kenan-Flagler Business School at the University of North Carolina at Chapel Hill. "The real bandwidth problem isn't with the Internet, it's with the mind of the consumer. What do they really want to absorb?" Balasubramanian says. "The whole point is to make it more meaningful, to send fewer but more effective e-mails."

One of Tralix's principles is to send e-mails only to people who actually want to receive them. T1msn, the joint venture of Telefonos de Mexico and U.S. software giant Microsoft, avoids spamming by asking customers to "double opt-in" before receiving the company's newsletter. Customers provide their e-mail address and then the company sends an e-mail to confirm their identity and their desire to subscribe.

Embedded. The interactive newsletter features what Tralix calls TEMOs, or Tralix Embedded Mail Objects, which are pares of the e-mail that a user can click on, type in of check off. As users interact with the TEMOs, T1msn's Tralix database is enriched.

"TEMOs are what make us able to keep track of every user and what they do," says Gonzalo Alonso, sales director for T1msn. "You never leave the newsletter to go to a Web site, so everything you do inside the mail, I keep track of. If you only click on entertainment topics, I know that."

Tralix, which acquired its first customers in 2002, plans to expand to the United States this year. Its has a patent pending in the United States, and the company has a small data center in Austin, Texas. A full office in New York is expected to open by June and a San Francisco office will follow, Ascencio says. He says Tralix is in talks with American companies such as Hewlett-Packard and Citigroup, Banamex's parent company.

Ascencio doesn't expect quite as good of a response rate from e-mail users in the United States. "The matureness of the market there can be both good and bad," he says. "Consumers there are more skeptical ... and more concerned about the spam issue."

U.S. chip giant Intel Corporation has decided to invest in Tralix, Ascencio says, money his company will use to finance global expansion. Erik Lopez, Intel Capital's strategic investment manager for Mexico, would not confirm the investment decision, instead saying that the two companies are "in ongoing conversations."

Lopez nevertheless says that Intel thinks Tralix technology could be used for a wide variety of e-mail purposes, such as corporate bulletins, human resource management and company-customer communication.

"We see that [Tralix] has a fairly strong potential beyond the marketing aspect," Lopez says. "Any company that is becoming more and more reliant on e-mail as a primary means of communication ... would have an interest in seeing something like this."