Links can determine a Web site's credibility and ranking in search engine results listings. Finding potential link partners, however, isn't always easy for SEO experts. Jennifer Van Iderstyne shares a few ideas on finding and approaching sources to "ask, beg, or barter for links." She explains one of her favorite ways to search for link targets: by "following other links, or as I like to call it, searching down the Rabbit Hole. You never know where you're going to land next or what you're going to find when you get there."