They are an extremely useful tool
Linking from outside your own website is not a new concept. Though it just may of not had the name previously. I have known what they were for a long time, yet never heard them called back links. You can try to get websites to agree to post your link and in turn you would post theirs, however they can remove it at any time, and you should of course have like traffic on both sites. No one will want to link to your site if you do not get any traffic. The better answer is to find a linking service to get and keep quality linking to your site, which will ultimately bring you more business.
