And you are getting something valuable in return. It's probably a good trade for many, especially when they are doing something like summarizing a public article.
I'm not so sure. I have agents that do categorization work. Take a title, drill through a browse tree to find the most applicable leaf category. Lots of other classification tasks that are not particularly sensitive and it's hard to imagine them being very good for training. Also transformations of anonymized numerical data, parsing, etc.
