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.
Affiliate marketing overlaps with other Internet marketing methods to some degree, because affiliates often use regular advertising methods. Those methods include organic search engine optimization (SEO), paid search engine marketing (PPC – Pay Per Click), e-mail marketing, content marketing, and (in some sense) display advertising. On the other hand, affiliates sometimes use less orthodox techniques, such as publishing reviews of products or services offered by a partner.