Do you think the average reviewer can review a friend's book and still be objective?

That's a tough question. I personally would not review a friend's book unless he or she knew I was going to be as critical of the book as I would any other book. However, I'd probably save my "review" for drinks and conversations at the bar and help my writer friend improve, if I thought it was necessary. Then I'd buy a round of drinks.

Do you think a review written by a reader has less value than one written by a professional reviewer? What defines a true "reviewer"?

All reviewers are readers first, critics second. That's how it should be, at least, so I think a reader's review should hold just as much influence as a professional reviewer as long as it is written well and does not fall into the traps that a lot of beginner reviewers fall into (the "facile praise" or overly negative stuff we mentioned earlier, for example).

In fact, I'd rather read a "reader" review than a professional review, and I have found that sites like Blogcritics, PopMatters, and Bookslut all hold their own against the established publications such as The New York Times Sunday Book Review. Every reader should take a close look at all of these publications when looking for good book reviews.

I find that to be very unethical. It's one thing if the publisher sends the reviewer a free copy of the book in return for an honest review of the book, but paying someone for positive publicity is flat out wrong. There's no possibility for being honest or objective when money has been handed out.

New reviewers should be careful of publishers who do this type of thing. I personally don't know of any specific examples, but I'm sure it happens, and a new reviewer should realize that this is not the common practice.

Do you keep the author's feelings in mind when you review?

Only to the extent that I want the author to know my opinion of the book. I don't worry about whether or not my review will hurt their feelings, but I do want the author to read my review. After all, if I took the time to read and then thoughtfully analyze an author's book, I want them to know about it. Like I said before, my reviews have elicited responses (and ensuing debates) from authors, so I definitely enjoy that.