You are correct, you can get a free link cloaker. There are many of them.
What you do not get is the ability to keep your affiliate links in one central place, group them into categories, and put your own custom adbar, or flyover ad on the affiliate page you are promoting. This is a very powerful feature that can increase your chances of a sale dramatically.
Plus you can set your cookie and redirect directly to a sales page, or any other page for that matter with the skaDoogle Link Cloaker.