Anyone that deals with marketing and advertising on the Internet knows that link popularity is one of the main causes for high rankings. And as we all know, high rankings lead to more traffic, which in turn leads to higher sales. The biggest problem with doing link exchanges and using programs that automate the process is that you run the risk of gaining bad links on your site. Bad links lead to reduced link popularity and in turn can eventually lead to being banned on search engines. Everyone can agree that if you are banned from a large search engine like Google or Yahoo, then your website is in trouble. I have come across a few places that allow you to grad good reciprocal links from ranking sites. You want to do more reciprocal linking because it provides an incentive for both sites to keep the links up.
If you already have a large link directory on your site, you might want to think about using the program Arelis. This gives you the power to control all your links and make sure they are still linking back to you. It also gives you the control to find more targeted links for your website.