Serious income. Serious income to me means the funds to live off of or greater.
This blogging business is hard. It takes massive massive numbers to get income level money. If you get 25 cents per click and you need $3,000 a month to live think of the clicks...
That takes 12,000 clicks per month.
12,000 clicks per month at a healthy 4% CTR means you need 300,000 visitors per month. (that's 10,000 visitors per day)
Of those 300,000 visitors how many will re-peat legitimate clicks for you again per month? How many are "unique" visitors that will stay at your blog and look around?
I'm not saying all of this to be negative, just being realistic. To even make a base living it takes massive visitors per day. So IMHO, just have fun with the blog and when you make money, count it as a bonus.
Those numbers are intense, that is why I have been taught to spread my eggs into a few other baskets per say. While you are on the Internet working on your blog, there may be a few other endeavors you can take on and bring in some extra cash so as not to rely so heavily on your blog.
The money one is a tough one to swallow but probably is the right attitude to have. I think if we could all live off of the money we get from our blogs, we would be "living the dream". Reality is probably that we wont be able to do that very easily... especially if blogging isnt your full time job.
On the flip side, a lot of people get a good following and are able to make extra money from there blogs, which means more traveling! And that never sounds bad!
All good things. I might add that you shouldn't junk up your blog with a bunch of slow loading flash programs, videos and banners. If it is slow to load, most people won't hang out and wait.
I think Karen Bryan of europealalcarte should chime in here soon, specifically on the matter of the challenges of making travel blogs sustainable. She always has interesting things to say about that.