To me the most important aspect of attending a business school is to look at the job prospects. Some business school are more renowned for certain majors. For example, a school might have a better finance program hence reflecting higher job offers in finance roles. Business schools will publish statistics about job placements in each major and also break down other facts such as demographic data and GPAs. It's important to do your research and network with current students to understand the subtleties that the data will not necessarily explain directly. For example, the courses related to finance and the clubs offered at the school may be more geared towards investment banking. If a higher number of investing banking job opportunities are given to the students at the school, then that might also raise the average salary calculated. The average salary, therefore might not be a good indicator of what your business degree may be worth upon graduation. There are many subtleties that differ amongst business schools and the best way to learn about them is to converse with current students and to research beyond what the tour guide may say to influence your opinion.
Best of luck!