I was using the "Real world practice function" and I stumbled here: http://duolingo.com/#translation/0ac5871b12920cc1ae17f7bd152949dd?index=2 . I don't think advertisements should be into the pool of articles to translate. If so, I would like to be paid. Did it happen to you as well? Do you find it fair or not?
It is actually duo's business model to sell our translations and in turn provide the service for free. So, it's quite natural that we will translate some articles they can make money with. As long as there is a good balance with -say- Wikipedia articles, I have no problem with it. This keeps duo self-sustained.
http://duolingo.com/#/translation/b2f3bf0baec33bb1e558cc69bff2834b Here as well. I am shocked. Indeed.
I wonder if Duolingo people know that some contents could be perceived as ads. Maybe it's not even intentional. If I would run a site so great like this one, I wouldn't like that some contents are not perceived as helpful only. I can go on translating only other stuff, I know. Anyway, it seems this thing disturbs only me.