When placed on the same site as your product, you're already at a disadvantage because everyone that goes there will believe it to be biased (with good reason). One of the things that bothers me the most w/ these is when someone points out their own product with all green checks, and the competitors with obvious missing points (red x's). It's typically easy to find a skewed perspective that gives you a 100% on features, and the others lesser so -- these are difficult to "believe".