As you know, Google has been battling the whole paid-link idea, trying to keep search result quality up by stopping “unnatural” PageRank distribution. But here’s a thought: Aren’t affiliate programs paid links? Would half as many people link to Amazon pages if it weren’t for the Amazon Associates program? Amazon is paying people to link to them, and refer customers. But tell me they didn’t think somewhere along the line “Hey, this would increase our search rankings.”