For continuous link building purpose which technique is best?

For continuous link building purpose which technique is best?From the previous forum I got the knowledge that social bookmarking can be used only once.So which method is better to do continuous link building blog commenting or forum posting?

It has to be both...None eclipses the other. You, however, need to be picky about where you intend to comment/ post. I use Keyword Country to find niche-related, authority blogs and forums to post on...It works for me.

And wait, social bookmarking can be done just once? Where did you pick that from?

Then please explain how you make using social bookmarking for your promotion?And which technique you are preferring for link building?

For continuous link building there are many SEO off page techniques like- P.R., Article, Forums, Blogs etc.. you can use any or all for continuous process.

- Ensure you have included a catchy headline, updated quality content and a crisp, convincing description about the product.
- Categorize your URL pages to list them in relevant categories
- While adding the URLs add appropriate description, keywords, tags and subject
- Integrate social bookmarking buttons on your website to make bookmarking easy for the users

Apart from social bookmarking, other techniques on my link-building list include:
- Submitting RSS feeds to feed directories
- Participating in social networking sites and related communities
- Writing guest posts for related blogs to your niche

I use ‘Keyword Country’ to design my link building strategy around traffic pulling keywords and to monitor link-building strategy of my competitors. Pretty satisfied.