Hi there - I actually welcome your skepticism on this one - there's a lot of people claiming a lot of things online these days.
The reason I actually revealed the amount I've made with Amazon in this post was simply that I constantly get people telling me that Amazon is impossible to make good money with because it's just lots of tiny tiny commissions (ie 5% of a book sale isn't much).
In terms of what makes me my money - if you read the article you see that I'm linking to my photography blog. That is my main blog (in terms of both traffic and earnings). I do make some from ProBlogger but it's small in comparison with the photography one.
Yep I sell an ebook from my site - it's done ok but it's not my main income source by any means.
In terms of inflating the amount - not quite sure how to 'prove it' - I don't like to post screenshots of earnings pages because people tend to say they are photoshopped - but if you know anyone in Melbourne Australia and want to set up a meeting I'm more than happy to show them my reports live and have them verify them for you.
I'd also say that if I was going to inflate the numbers I'd probably go a little further than I did - $119k in 6 years isn't really the most amazing claim of making money online that I've heard :-) It's more than pocket change but it's small time in comparison to many.
Again - happy for people to be skeptical - I actively encourage people to be in this game, there's a lot of big claims, hype and empty promises going around. I myself pride myself on not promising big easy money - in fact I've written many times on how hard it is to make this kind of money, I've worked my butt off for 7 years building my blogs up - it certainly doesn't happen over night.
Happy to chat with anyone who wants to raise concerns over my approach and shed as much light as I can on the topic.