The best thing about this is that you need not have all the traffic in the world. If your blog is No.1 in a category which has a reasonable sized audience then opportunities will find your way. Mine is focused on India & Motorcycles... there are bigger blogs which cover both cars and bikes but for bikes, I am No.1.
This blog of mine is not the best money maker out of my several projects, but I love it more than others because it provides a lot of value and I have gained a lot of new experiences and friends from it. Its more of a hobby!
I was invited to a motorcycle trade exhibition in China with 100% sponsorship and my only obligation was to post 5 articles on specific topics on my motorcycle blog after I came back.
I also met other bloggers from my niche... from Spain, Brazil, Canada, USA etc. The guy from USA was from Motorcycle.com! (a very big site). We went to motocross championship, visited exhibits, motorcycle factories and interviewed big shots in that industry.
Each one of us had an escort who also acted as an interpreter as well. And they were beautiful :p
In one phrase: I had a blast for 4 days!
You can read my full story (with photos) here:
My Experience In China - The CIMAMotor 2009