NYDesignGroup is a huge advocate of reciprocal links. When you link one website to another website, it provides a number of internet marketing benefits.
The main reason is that it increases the amount of traffic to the client website. When you have a link on someone else's site, both parties benefit from the internet marketing of the other (especially if you both aggressively promote your sites.)
It also helps in the client's ranking with major search engines, higher status and more credibility is gained.