Nice post , i think just from psychological aspect " users " would rather hear about your product or service online from somebody who has used it and is not trying to sell it. This phenomenon has been around a while before websites and all that. this is why people who go into sales always talk about letting the product sell itself , if you try to actively sell a product its human nature , to be sceptical. Think of how we hate sales people in general lol . Content writing took up this uproach long ago , using phrases and questions that are agreeable to users or make them have to read more. But i like this , that you think its going to become a bigger feature in 2018 , even if not by lets say google giving it any ranking value ( which im sure they will once they can regulate and authratize such content.) The very fact the users will see their peers as you put it will do much for credibility and trust. I was thinking voice for 2018 before this , but now im not so sure .