Hello there. I was searching thunderbird books on google, and came across one with an interesting title, so I went to check it out on Amazon. When I scrolled through the reviews, I quickly found most of them contained a sentence or two like this:
I got this in a giveaway and this is my honest opinion.
I received this book for free and voluntarily reviewed.
I received the e-book for free and voluntarily reviewed it.
I received this ebook free in exchange for an honest review
Only four out of the twelve reviews do not say they are reviewing it because they got a free copy. Is this allowed? Personally, I find it a little odd, as people could be biased after you gave them free things. Or is this more common on Amazon?