In 30 second can you write minimum 5 logos that you remember and sketch their logo. If you can do it, that is the answer how important your logo.
Human usually are easier to remember graphic than word. By having logo that simple and easy to remember, it makes your clients easy to distinguish between your product and others.
Not only that, you need a logo that can be implemented to other platform such as letter, apparel, signage so it will gain credibility of your product.