I think what Daniel is saying is that on social news sites, popular posts tend be popular because they're popular. I don't think we can attribute Google's succ

I think what Daniel is saying is that on social news sites, popular posts tend be popular because they're popular. I don't think we can attribute Google's success to cumulative effects: I suspect that you can see cumulative advantage effects only when objective quality is difficult or impossible to measure. Taste in music is extremely subjective - it's very difficult to measure the quality of music independent of its popularity. On the other hand, the objective quality of search results can be measured by independent testing and feedback - it's not perfect - but you can get a much better measurement of quality for search than you can for music.