For myself, I spent anywhere for 3 to 8 hours a day, more the 8 hr days than less, but suffice it to say, lots and lots of time, learning how to do back links, links to my other blogs, links to other sites I began writing for, posting advertising to join me on Hubpages on Free Advertising Sites, applying Key Word SEO techniques, and developing some Niche(s), all resulting in growing my Adsense account up to $50 in just 6 months. Learning takes time, effort, and perseverance; I was aware of this from the get-go. It took me 5 years before I was a confident machinist; so, I understand that to become great at anything takes time.
My only regret with HubPages is that after all this work Google's Adsense people deemed I posed a risk to their advertisers and they deactivated my account. "Boom", just like that they took back the $50 I had just reached and they put me out of business so to speak on HubPages. See with HP's, your Hub Ads don't work unless you have an Adsense account and the Amazon Ads never did bring in any money, so I was done. When I checked my Hubs I saw Google, who said I posed a risk to their Advertisers, still was posting those same Ads along side my Hubs, so I changed all my Hubs to non-commercial type Hubs, and turned OFF the Ad feature in the Settings section. Bottom-line, making money on HP's seems to be really unprofitable given the thousands of hours it takes to develop even a minimal amount of money as compared to any other "Job."
I recommend, if you are a confident writer, to develop a relationship with various Magazines and Newspapers you enjoy and writing directly for them. Most are looking for stories they can use for fillers and many are interested in finding new talent. There are no free lunches in life and putting ones hopes in a company like HP's works only for a certain few. I've read more stories of failures than I have of stories involving great success. Though I seem to be one of those on the failure side, but I've learned a lot during this time and I am already writing for 6 other online sites and am making connections with our local paper and a few other papers I am familiar with. One Editor as me to send her some samples of my writing for fillers and has offered to pay me for using them. So, if your dream is to become a Freelance Writer, don't be discouraged by seemingly poor success, use what you have learned and keep pushing forward and upward! I wish you great success in all your endeavors!