Are roses the most popular flower for events?

I have an event rental and decorating business and I would like to offer flowers such as doing bouquets, centerpieces, cake flowers, arch decor. Nothing to extravagant though since I am not a florist. I'm just trying to help those on a budget. Anyway my question is: I want to only offer roses, is that okay? Why/Why not? Should I keep it simple that way or offer other flowers? Is it really that serious to need to offer more than roses? Does it hinder my business in anyway? Thanks in advance!