It's a definite flaw, encountered in so many places with varying degrees of danger, obviously some people are going to try and maximise their results by abusing

It's a definite flaw, encountered in so many places with varying degrees of danger, obviously some people are going to try and maximise their results by abusing it. When I think about credibility though it quickly appears to be a bit of a mine-field, highly context dependent. If PG writes an article people are going to attribute a huge amount of weight to it. Obviously he is very credible when it comes to a lot of subjects, but context can tell all. I'd say if he wrote about how paste engagement rings were going to be the next big thing there'd be one or two embarrassing proposals on Youtube within the month. But if he wrote on why paste jewelry is the next big thing in fashion businesses there is obvious weight (whether or not it's correct) to that opinion. So I'd say matching context with popularity, and figuring out transferability of credibility are where this can be disrupted.