effective link building

If you ask for effective link building then you may get many similar response like:

forum posting,
blog commenting
social bookmarking
article directories etc.

but they may not be effective, you have to do it effectively. For example, if you are doing link building using article directories then you have to submit fresh articles to only top article directories for greater benefit.

On the other hand if you are doing blog commenting then you have to choose which blogs are effective and relevant to your blogs and site.

Link building means it is not to through your links anywhere, it should be thrown at right place....
If these links are getting some traffic then it is also beneficial in terms of SEO.

One method of search engine optimization is using one way links building services. Google uses many different elements to determine page rank. Links are extremely important to Google and the more links you have pointing to your website the better off you are. However, it is not always as easy as that. One way links are very difficult to get and maintain. One Way Links helps well to climb up well in SERPs.

Yes, these are one way links so they are good but you have to do effectively means you have to do regularly, you have to do slowly and try to build links on related sites, forums, blogs, directories etc.