Yes .. I am agree with Muzz . The exist link should be quality.

Link Building... Time-intensive. Frustrating. Sometimes confusing. Yet Unavoidable. Because ultimately, it's still the trump card for higher rankings.

All link building methods are helpful you to increase your site link popularity. If your site have more incoming links from relevant high page rank sites, all search engines will rank your site at top in their search results. So, build more back links to your site using with the different link building methods like article submission, forums posting, blog commenting, social bookmarking etc..

I prefer blog Posting, forums & Bookmarking .