Which is more Effective Forum posting or Social Bookmarking?
Khem,
To answer this question, might require some clarification.
1. What effectiveness are you measuring? SEO value / User Traffic / Brand Awareness?
2. What is your goal for the above three areas?
In answering this ahead of time, I would break things down in the following:
SEO - Both - Assuming that you have do-follow links and properly varied anchors, that won't kill your profile, you should do fine with both
User Traffic - Forum Marketing wins in my book, unless you promote something that goes viral via a social channel. Unless you are on reddit, most viral activity starts from some social channel or video medium of some sort.
Brand Awareness - Forum Marketing - Whether you are building an individual or business brand, people connect quicker on forums.
Heck, I could be way off base on what you are looking for, but hopefully this helps you!
Let me know if it does!
Shawn