Don't Believe Everything You Read Online

After browsing the Internet in search of xmas gifts from various people. I realized that I trust reviews and recommendations by online "users" way too much. Why should I trust a user that I have never met or even seen in real life? I liken this to asking a guy standing in front of a restaurant if it is any good. I don't know about you, but I would only take his advice with a grain of salt for a few reasons:

1) He could have very bad taste.
2) This guy could be working for them.
3) He could be bullsh*ting me.

But when reading reviews online, the dynamics of the situation are completely different. Why is there so much credibility?!
Is it because the reviewer is competent enough to write a paragraph? Or is it because the reviewer took the time to put his thoughts online?

Either way the reviewer is just giving his/hers opinion on the subject and that is just that, SUBJECTIVE.

Thoughts?