Seeing an advertisement for a question on the Science Fiction & Fantasy SE on the main page made me wonder if it would be useful to allow those with low reputation to financially pay for more attention to their question. While this would to some degree buy reputation (as scoring correlates with views), it is not a direct purchase (and a user could use external advertising toward this end).
For professionals new to Stack Exchange, the cost of such advertising would not be a significant burden, though to students (who are generally less well-positioned financially) paying for advertisement would be more problematic. (On the positive side, this would reduce the chance of simple questions cluttering the featured page; on the negative side, this would discourage drawing attention to some useful and not easily answered questions.)
To reward answering such questions, giving an answer might be treated somewhat like a review activity such that answering such questions can earn bronze, silver, and gold badges (according to the number answered). (This may not be sufficient motivation for answering, even though a good answer to a question getting more attention would earn more reputation.)
I don't know whether such advertising would only bump the question once on the main page and active questions list and place it on the featured questions list or if it would also bump the question periodically (perhaps according to the amount spent on advertising?). Side bar notices would be another mechanism for drawing attention.
I suspect that the benefit to low reputation users would not justify the implementation cost and the potential issues of abuse, but I thought the idea was worth mentioning (it seemed interesting to me).