From a SEO point of view how much are social bookmarking/directory links worth in comparison to highly relavant links? Would 1 highly relavant link be worth more then 100 social bookmarking links? would appreciate replies from experienced marketers who have measured the link value of the afforementioned.
It depends where the social links come from etc. One link voted high on reddit or folkd is worth 100 dead links on any website in the world, mainly because of the traffic.
I would recommend you start "compare marketing". See how your rankings are using some of the social links to see which ones give you great results. At this time, it looks like Facebook is winning in the link war. One of the things I like about Facebook, is you only need to put it on your site, and as other "Like" it, it goes to THEIR friends, and as those friend "Like" it..... It's a snowball effect. However, Google may stop looking at those in the future if they get too carried away. The more powerful the sight (say Amazon.com for instance) that has your link, the higher the link value. If you are interesting in learning more about this process, you may visit "youfounditworld" (that's a .com) to get more in depth, straight forward information. They laid it out for me so simple that a 2 year old could do it.
You could always read about how Google Page Rank works. Then you could try to figure out how the Bing/Yahoo Algorithm works. And then magically you would have an understanding of which links are valuable and why. Or you could just fly blind and hope for the best. Because both companies tell you what you need to do to rank.