Crowdsourcing allows niche markets to thrive. Pandering to the lowest common denominator allows the shallow to profit.

I upvote replies to my posts unless they are themselves begging for upvotes, or offering such a meaningless generic comment that I can't tell whether they read what I wrote. Quid pro quo demands are not cool at all, and while I see a potential use for offering such deals, it just feels distasteful.