Retirement Kitty

Cloaking means that you hide something from the user.
In this case you don’t want the user to see where you are sending them when they click on your link.

Someone might be put off and un-trusting of you if they know you stand to make some money off of their purchase. Purchasers often think that because you are making money as part of the sale, that they are paying more for the product, and that they may be able to obtain the product cheaper from the maker of the product. This is almost always untrue as makers and distributors charge the same for products in all most every market.

By cloaking your links you can also retain your own analytics on what is being clicked on, otherwise you must rely on the affiliate programs analytics to let you know which affiliate links are being clicked.
The analytics vary from service to service and keeping them inhouse keeps everything in your portfolio consistent.