The cost of sending Michelle Hals to Hamline University, a private college in St. Paul, Minn., is a hefty $18,500 a year. So Ms. Hals's parents, who pick up part of that tab, were pleased when they learned that the university offers a four-year graduation guarantee. Started two years ago - the same year that Michelle applied as a freshman - the graduation guarantee ensures that the university will pay for a fifth year if the student is unable to get into a class he or she needs or is misadvised. ''Hamline is a very expensive private school, and when you're looking at possibly paying two or three years more at those tuition prices,'' it can be devastating to the pocketbook, says Cindi Hals, Michelle's mother. ''The graduation guarantee was a good selling point.'' In an age of shrinking college budgets, which sometimes translates into shortages of classroom space and staff, many students - particularly at large public institutions - are forced to spend an extra semester or more in pursuit of a bachelor's degree. Most of the time, mom and dad foot the bill. Now, a growing number of colleges from California to Wisconsin are realizing they have a responsibility to see students graduate on time. Colleges see business side The graduation guarantee is just one example of the different strategies colleges are using to market their ivy-covered campuses. Driving the recruitment frenzy is increased competition for a declining pool of qualified college-bound youth - a trend that is prompting institutions of higher learning to become more market-savvy. ''Colleges are beginning to look at themselves more like a business,'' says John Lawlor, president of the Lawlor Group, an education marketing firm in Minneapolis. ''Not a cold-hearted business, but the business of higher education. They're beginning to realize you can't be successful if your public isn't buying your product ... so they're putting themselves in a situation where consumers will buy the product,'' Lawlor concludes. ''Universities are realizing they need to do some of the things business folks have been doing since the '70s,'' adds Tim Dodge, president of College Marketing Technologies Inc. in Crystal Lake, Ill. Selling to a target market One of these strategies is geodemographic marketing, a service Mr. Dodge's company performs for dozens of colleges across the country. It involves building a profile of a school's student body by examining the kinds of students it attracts. ''Once that's been done, we can identify those areas geographically the school can go to find more students that look precisely like those who have come in the past,'' Dodge says. ''Colleges build a rich portrait of their best customers so they can more effectively reach them either with advertising or direct mail or whatever the vehicle might be,'' Dodge continues. ''It's trying to work smarter rather than harder.'' Colleges are peddling their product in other ways, too. An increasing number of institutions offer price guarantees where tuition remains at the same level for four years as long as the student is working full-time toward a degree. In other instances, the tuition will only increase by a certain percent. Time-shortened, or three-year degrees have also grown in popularity. The most intensive recruitment strategies are coming from the private colleges where tuition is much higher than state colleges and where pressure to fill the classrooms is enormous. ''We're one of the hungry colleges,'' admits Terry Lahti, dean of admissions for Kalamazoo College in Kalamazoo, Mich. ''Despite the selectivity of the institution, we have to work hard.'' To attract potential students, Ms. Lahti and a team of counselors focus on relationship marketing where alumni meet prospective students at a small gathering. The relationship is pursued, and even faculty are involved in writing personal letters to students. At Hamline, the four-year graduation guarantee requires that students take eight courses a year, meet with an adviser twice a year, and declare a major by the end of their sophomore term. It was introduced more as a marketing tool than anything else, because the university's graduation rate is already fairly high; two-thirds of students graduate in four years. Thus, there is little risk to the university of having to live up to its promise. The guarantee signals Hamline's commitment, says Scott Friedhoff, dean of undergraduate admissions. Though it is difficult to measure if it's attracting more students, he says the university has had a record number of applications in the past three years since it began the guarantee. 'Hold accountable' attitude One of the few state universities to adopt graduation guarantees is the University of Indiana, which will start its program, called GRADPACT, in 1996. ''The myth is that it takes a long time to graduate here,'' says Don Gray, a professor of English. ''The story in the state was 'my kid can't get a class to graduate, and it's your fault. It turns out usually that a kid could get a class, but he didn't want it at that time or he didn't want to take it with that teacher.... This is simply a way to clarify that and make the university and the student both responsible.'' While four-year graduation guarantees may help institutions become more accountable and perhaps more enticing, the majority of students now expect to spend more than four years pursuing a degree, says Joyce Scott, vice president for academic and international programs at the American Association of State Colleges and Universities in Washington, D.C. Many are adults who attend college part time; they are part of the reason graduation rates are so low at some universities. As colleges increase their strategies to draw more students, some in higher education express concern. ''The cost of marketing is tremendous,'' Dr. Friedhoff says. ''Half the cost of a can of soda pop, for instance, is advertising expense. That can't be the way higher education goes. So while we may be getting a little more businesslike in some aspects, I think it's our responsibility not to get carried away.''