Here’s the simple formula!
to monetize your blog in this post on TechCrunch on the State Of The Blogosphere: Get To 100K Uniques, Make $75K/year
I have my doubts about the possibility to turn a travel related business blog into a money maker but for most in our industry that’s probably not the point anyway. How these travel blogs will develop down the road and whether revenue can be derived from them, of course, remains to be seen.

Totally agree. Monatarization in this scale, without anything than a blog is impossible. Now, if there are books, tours and other products related to the blog, as for example Rick Steves, this is very doable and more.