If you write quality hubs and keep adding new hubs, you might even cross that $5 per day mark. I've seen people making a lot more than that per day.
It takes patience, determination, and the willingness to write. On HubPages, Google is your best friend. If your hubs are not ranking well on Google, than you will not have much success. Although, once you write a hub, your first traffic will be from HubPages.
To sum it up, write great hubs with keywords that pertain to what you are writing. All these will help when ranking your hubs on Google and other search engines.