Yes, I think you are right. @fyrstikken & co. is working with an add based system on Steemit. If I have understood correctly the ads will show up after the posts are paid out to the producer, thus they are suppose to ad extra value to the posts. You should probably check out yourself, as I am not updated on the progress of this project. However, I have no reason to suspect a lot of fraudulent ad content on Steemit, as this would surely be reported pretty quickly.