Without doubt low quality links have been losing their ranking power for some time now.
Forum profile links and weak referral links such as pingbacks have very little appreciable effect on rankings. What’s more they just mess up the web with spam and are best avoided.
These days such links are usually used merely as a means of diluting a site’s anchor text ratios and keeping its backlink profile diversified with different link types.
If you are building these types of links it is best to build them in small numbers that way if they are ever targeted by Google (which they probably will be) the effect on your site will be minor.
Although low quality links are a good way to help you diversify your anchors and link types they do no real good for your site in the SERPs.
However, there probably will come a time when these links actually hurt your site. We have seen the madness that ensued from the Penguin update and just how severe Google can be in their views of what is quality and what is not.
Although low quality links do not directly hurt your site or your rankings at this current time be aware that this may well change in the future. Any link building carries a risk these days.
Google most definitely wants to build an algorithm that can automatically hurt sites that use seo and are working feverishly to make that a reality.
So not to make this easy for them it is best to build only good quality links as your tier 1 and try to do the same at the tier 2 level. Once you dig deeper in the tiers it is fine to use lower quality links.
As tier 1 links we advise you to build as many relevant contextual links as much as possible ensuring you adhere to the anchor text ratios outlined in another section and by also adding some high PR backlinks to the mix.
Be sure to follow the detailed steps outlined in our link building sections.
As Google changes the rules we will update these strategies. So you can be sure that the tactics outlined are proven to produce solid Google rankings that are designed for the long-term.