I used to be a "dancer" and I always had rubber bands for my money. So there you have it, people who deal with alot of cash, may use rubberbands to organize it.
If someone has some rubberbands and is using them to hold onto large wads of cash they may not get a regular paycheck. For example they may be a stripper, drug dealer or have some other unconventional career. They are a rubber band man, or woman!