Ah...now I feel I can post in your thread! The original question had me thinking were you looking for something I could not comment on....
I use my iPad to give pressentations...several per week. I love using the iPad for this because it lets you zoom in on things in a way you simply cannot do in a traditional PC. That pinch and zoom is wonderful for technical talks I give.
I also do a lot of reading for work on my iPad. That was my primary reason for dumping my iPad 2 and getting a retina iPad. Funny thing, though, is I can still do the reading on my mini, too, and since it is so small and light, it is easier to sit on the couch and hold it in my hand to read. And I do lots of this kind of thing. My iPad are a big tool for work...all linked to up to dropbox. Since getting my iPad, dropbox and become even more useful for me since I can work in the same files at work, at home, or whatever I am.
So, yes, iPad is a big part of work for me. The sheer number of apps is a big plus, too. I found this one app that I actually plan to use a lot over the next several months -- for work.
So, while I don't feel comfortable saying I make money with my iPad, I do feel comfortable saying I use my iPad in my work, which is how I earn a living.
I use GoodReader the most, for work. There are a few others that I'm planning on integrating into my daily workflow.