Some subjects are much better paid than others, so although you may love the idea of writing about travel (badly paid) a better bet would be a niche like finance (much higher rates of pay). Check out the Pro Blogger job board for high paid freelance writing jobs – other places to look might be Textbroker or you can look at the “gigs” section on Craigslist.
Once you have that problem or need nailed, the next step is to validate that idea and make sure you’ve actually got customers who will pay for it. This means building a minimum viable product, getting objective feedback from real customers, incorporating updates, testing the market for demand, and getting pricing feedback to ensure there’s enough of a margin between your costs and what consumers are willing to pay.
In November 1994, CDNow launched its BuyWeb program. CDNow had the idea that music-oriented websites could review or list albums on their pages that their visitors might be interested in purchasing. These websites could also offer a link that would take visitors directly to CDNow to purchase the albums. The idea for remote purchasing originally arose from conversations with music label Geffen Records in the fall of 1994. The management at Geffen wanted to sell its artists' CD's directly from its website but did not want to implement this capability itself. Geffen asked CDNow if it could design a program where CDNow would handle the order fulfillment. Geffen realized that CDNow could link directly from the artist on its website to Geffen's website, bypassing the CDNow home page and going directly to an artist's music page.