Should You Trust Website Customer Reviews?

crevette asks: "I was looking on Amazon for some gizmo when I got a review from G. Cooke, TX, who is in the top 10 reviewers. Out of curiosity, I checked her reviews... She has 658 reviews, many on the same day, which include everything from knife sets to a plastic duck! She reviews many books on the same day... She must be spending hundreds of dollars on useless stuff every month. Worst of all, most of her reviews are 5 stars. Do you think those people are paid by Amazon or some company? Do you trust them? If not (like I tend to think) what can we do about it?"