If RandomHotelBookingWebsite.com announces that for every five reviews you write you'll earn a $5 credit which you can use for any booking on the site, why would that make you less likely to write a review? I can see that it might not make someone more likely to write a review (why bother for $5?), but why would it stop you if you were going to anyway?

The same reason that levying a fine on late daycare parents increases the frequency that they will pick up their kids late.

Monetary incentives tend to displace intangible incentives. This isn't necessarily a bad thing, IF you've designed your monetary incentives correctly...

No,it's not the same thing as the daycare example. The issue with daycare late fines is that they allow a person to "pay off" bad behavior, therefore reducing guilt and therefore increasing it's likelihood.

Here the OP is discussing rewarding "good" behavior. The psychology is not necessarily the same.

I am surprised at the negative comments on this thread. The feelings the OP is experiencing are real and even legitimate. The reality is that sites do profit massively from user contributed content, and an asymmetry in the perceived value of the transaction can clearly exist.

Frankly it amazes me that it has taken this long for rumblings like this to appear.

And this guy probably isn't a representative user of sites like these anyway.