I have always seen the Internet advise against it. Although I have made profit in this way.
There is a reason why people advises against that. Surely it is not good to rely on others opinions when making your decisions but there are times when you have to make an exception and look into their suggestions for some might actually be real or useful to you. After doing some research, consider analyzing all the informations at hand properly so you what to believe and what not. Hmm. Seems like common sense aint really that common.