I thought this would be an interesting topic or at least an interesting observation. If you google the life span of fish (for example) you'll most likely get someone saying 'from what I've read/heard' or just making a blanket statement. So you read on W forum/blog/article some info about a particular fish. Then you find the same info on X, Y and Z forum/blog/article. It's quite possible (and more than likely) X, Y and Z got the info from W. In which case it can't really be considered as 4 different sources. Just repeated info. To make it more confusing personal experience also differs since there are so many variables.