A lot of web publishers think the fastest way for them to obtain a good PageRank or PR ranking is to entice websites with higher PageRank to link to them. The notion is that if a page with a higher PageRank gives a link, its PR will be passed on. Although this is true in theory, the actual process is much more involved.
In reality, Google's algorithm for arriving at PageRank dictates that the amount of ranking a page can pass along to those it links to is its own rank for the page in question divided by the number of outbound links on that page.
What this means is that a site with a PR ranking of 6 won't necessarily pass along that entire 6 to a site. Say, for example, this site already has a single link on it and yours makes number 2, the ranking unit you enjoy is actually a 3. Adding to the quandary is the fact that the 6 is very likely only given to the home page, not the page where the links are. This is the page that will dictate the PageRank potential passed along.
Now, if you consider all those big hitting sites out there with great PR rates, but hundreds of outbound links competing for a slice of the pie, it becomes clear that they aren't necessarily the best to target for reciprocal links.
One of the better strategies is to target sites that are up-and-coming that have modest PR ratings. This might seem like an odd way to go, but it makes sense. As long as the sites are reputable, but have lower rankings just because of their relative newness, they can pay off in the long run.
The reasons these sites pay off better for long term strategy are many. One of the top is the fact it is generally much easier to get a newly ranked site to place outbound links. Plus, they are also more likely to put links on their front page. In addition, these sites don't tend to have a lot of links in place and good ones will have topic-related keywords that can help with Google. Also, it is much more likely to get these folks to use a keyword phrase in the link. All of these reasons are good, but the best for targeting these sites is that they tend to grow in PR over time. As they do, so will you.
Before jumping into find sites to target for reciprocal linking, it is smart to research them a bit. Avoid sites that have very low PageRank. Those that show up in the white or gray should be discounted. Gray, in fact, could be a negative draw for your site. These colors indicate sites without PageRank and can even indicate banned sites.
If you still find yourself wondering if this strategy will really work, consider the math behind it. An incoming link from a page that's ranked at 6 with only one other link will give you a PR boost of 3. A page that has a ranking of 8 with 100 links will only give you a PR boost of .08. The truth is in the numbers. Do the math and then choose sites that will benefit you the most.