[madskdc]

Many people, when done a favor, want to repay it. So when you praise a person to their boss, they're more likely to be on the lookout for opportunities to praise you in return.

Speaking from my own experience, I tend to be a quiet person who doesn't say much. However, since joining my current team, and having consistently received compliments from both managers and teammates (and seen the same getting passed around to others), it has lead me to make a point of looking for opportunities to do the same. It's become the norm to compliment others on their good work, and passing that up the chain and through official channels when the opportunity presents itself.