On one hand, long and ugly affiliate tracking links are a straight giveaway to people that you want to sell them a product (and people may be uncomfortable clicking on them). Therefore, making your link shorter and "nicer" looking will it give a more professional appearance. One of my favorite plugins for making links look "pretty" is the Pretty Links WordPress plugin.
In 1994, Tobin launched a beta version of PC Flowers & Gifts on the Internet in cooperation with IBM, who owned half of Prodigy. By 1995 PC Flowers & Gifts had launched a commercial version of the website and had 2,600 affiliate marketing partners on the World Wide Web. Tobin applied for a patent on tracking and affiliate marketing on January 22, 1996, and was issued U.S. Patent number 6,141,666 on Oct 31, 2000. Tobin also received Japanese Patent number 4021941 on Oct 5, 2007, and U.S. Patent number 7,505,913 on Mar 17, 2009, for affiliate marketing and tracking. In July 1998 PC Flowers and Gifts merged with Fingerhut and Federated Department Stores.