Why do I keep seeing reviews posted that are only a few lines long, but then the member adds a line that says 'see my full review at www..........'?

Why don't they just post their full review here? (not to include the book description)

Jeanne,

They probably have a blog they want you to go to. Some may not care, but a lot of other people hope to make money by having people subscribe to their blog, or they have ads on their blog which link to company product pages. Those companies will pay very small sums to blogs from whence the surfer came from. Sort of like how PBS makes some small amount if we go to Amazon from the PBS pages and buy something. 

When I make comments about book reviews in the forums, such as the History Forum, I link the book title to the book's page where my review resides. I don't need to make money from my book reviews, as I am a multi-billionaire. Still, it galls me no one has written a romance novel about me, as covered in another thread in the CMT forum.

Thanks for the explanation, Thomas!