Many good Backlinks come from Linkexchange, the Problem is that they are not one Way Links. Is it worth to always setup basicly 2 Sites on the Same Topic, so if you do Link exchang with other Webmasters you have only one way links? What do you think?
This is called 3-way linking. It is generally accepted that one site trading links with another is pretty useless as to improving your position in the serps. So the idea is that three sites exchange links.
One way links are better then link exchanges. Its going to be of little benefit to open a site just to exchange links. If you have 2 sites, offer to do a three way link. Your site A links to the other guys site, and in return he links to your site B. This is going to be a lot more effective the exchanging links between your own sites.
I always create 2 sites or more about the same subject. The advantages I get from it are numerous, but the two most important ones are: Being able to do 3 way link exchanging with both of us getting relevant links and I can write a lazer targeted posts and get a super relevant link back to my site.