Ask HN: Vending Machine Business Insight

I am currently in talks with someone to purchase a vending machine on my college campus. The owner claims he is selling it because it is too much of an inconvenience. I think it's because it doesn't make any money. What I would like to do is replace it's current product (ink) with various ideas and learn about this realm of business. I would love to get some neutral advice some anyone that wouldn't mind exchanging a few emails or if anyone has experience with owning vending machines, please share your comments and thoughts.