When I click the facebook share link and share a message through facebook from one of my clients, the icon next to the item in Facebook is my logo, not the clients. I can't seem to find a setting for each client where I can change their logo. Where is that?
Facebook's Open Graph protocol language allows you to customize how subscribers "Like" your client's campaigns on Facebook. This blog post will allow you to control the image/logo that is shown on Facebook walls.