I was an MIS major. The program basically sets you up for consulting on a wide range of computer related topics and then you specialize from there. Because of the mix of computers and business there also seemed to be a larger percentage of entrepreneurs than I’d guess there are in most majors.
Because computers are everywhere, and business basics are essentially used everywhere, your average day at the office could be just about anything. I always felt the MIS folks were more of a liaison between the techy folks and the rest of the company. You should understand both sides so you either get paid for helping everyone understand what the other side needs or for doing a bit of both jobs.
If you like the comfort of a large company, you’d probably be in the IT department and might be better served with a Computer Science degree or something similar. Small companies tend to value the flexibility. And if you have any interest in being self employed, being able to do a bit of everything can only help.
This isn’t to say that CS majors (or business majors) can’t be flexible, but MIS tends to be a hybrid between the two programs, so you learn less “pure” tech, and less “pure” business while learning a lot about how they interact. As with anything, where you go from there is completely up to your own interests and drive.
I always think trying to find a major and then a job you want to do is the hard way to go about it. The major will last 4 or 5 years, the career will hopefully last much longer than that and have a greater impact on your life. In my humble opinion, you should find an area of work that you’ll love, find a career somewhere in that spectrum, and then find a major that will get you that first job. Remember that 5–10 years out of college your work experience will matter far more than your major and it won’t matter if you studied MIS or Marine Biology or Philosophy if you can do the work. The major is just a launchpad to get you in the door.
Good luck with your studies.