Although 16 co-branded credit cards crowd the market in this up-and-coming country, the original remains the leader.Boris Buvinic, manager, sales and marketing, for Bank of Santiago knew he was on to something when his "The Bank of Santiago doesn't run... it flies" co-branding campaign with airline LanChile took off last year. Most other major banks in Chile followed suit-many also partnering with airlines-but none has been able to surpass Mr. Buvinic's tr ailblazing effort."We knew co-branding would bring major changes," he said, "and we knew we had to be first." Mr. Buvinic sensed the sea change after attending a seminar in the U.S. on co-branded credit cards. Then, a few month s before the Bank of Santiago's effort was launched, the manager attended a conference of South American advertisers, during which he noticed other banks showing keen interest in co-branding.The Bank of Santiago's campaign emerged in early 1994 against a backdrop of 30 competitors in a homogenous market where consumers didn't much distinguish one credit card from another. Mr. Buvinic, 36, set out to shake things up: He wanted to create a profitable new produ ct that would increase market share and tie the bank to MasterCard in consumers' minds. The way he achieved both goals was to co-brand it with LanChile, the country's main airline.Within a year, the bank had issued 50,000 of the sp ecial cards, moving to a 50% share of the MasterCard market from its 39.1% share-a change which boosted the bank's total market share (for Visa and MasterCard) to 23% from 14.9% Today the Bank of Santiago has a total of 140,000 val id cards issued. The campaign doubled the number of purchases using the Bank of Santiago MasterCard and pushed up amounts charged 64%, compared with 38.8% for its nearest competitor, the Bank of Chile. The Bank of Santiago's total billings (interest rates, annual commissions) rose 102% in the year following the campaign launch.In the first stage of the $1 million yearlong push, Mr. Buvinic, along with advertising agency Matte Mendez in Santiago and Pablo Val des, then head of LanChile's frequent flier program, aimed to position the product and brand names, along with educating buyers about co-branding. The effort was also an integral part of the bank's overall marketing strategy of bal ancing its image as a technological leader along with the idea that it remains a friendly place to bank. The campaign resurrected two characters, Ismenia and Perico, who starred in ads that revolutionized bank advertising back in t he 1970s. The groundbreaking ads, driven by TV, showed Perico on his bike, wishing for a car, and turned the ad slogan "Buy yourself a car, Perico!" into a national catchphrase.In 1995, the actors playing the popular characters r eturned to national television ensconced in both a car and a comfortable home, neatly mirroring the economic ascent of Chile's society into the middle and upper classes.Print ads and outdoor boards were also part of the campaign's media mix, as was direct mail, which began with a piece resembling a plane ticket sent to consumers selected from the bank's own database. A second TV spot showed Ismenia and Perico enjoying a holiday in Mexico, to make the fake ti cket's promises more real.A June 1995 study by Audit, a market research company, found that 40% of those surveyed spontaneously recalled the Bank of Santiago's co-branding campaign, compared with 14.3% for the Bank of Chile's and 1 1.2% for Citibank's.