If you have a review site where on the front page you list all the different websites available in your niche. These are affiliate links, and I'd like to place an image next to the link with some text for each one. Would it be illegal to use an image of their logos next to the links? I know that it's not allowed to use others logos on your own site, but if it's an indicator of where they will end up when clicking the link? If not, what image would you use instead to give a picture of the site you're sending them to?