Source: http://www.free-seo-news.com/newsletter698.htm#facts
Having the wrong type of backlinks can get your website in big trouble when Google rolls out an algorithm update. So how do you get good links that can help your website?
1. All automatic backlinks are bad and have no positive effect on the rankings of your site
– You don’t have to worry about automatically created backlinks that use the rel=nofollow attribute.
– Avoid a penalty by getting rid of automatically created backlinks.
2. You won’t have much benefit from a link that is easy to get.
– Uploading an image to imgur.com and putting a link to your website in the description will not do any good to your site.
– A link that is easy to create won’t have an effect on the rankings of your site.
3. Getting backlinks from pages with high PageRank makes link building more difficult.
– Linking to a page with low PageRank is still good as long as the website has an overall high-quality.
4. Use your common sense when looking for a web page that could link to your site.
– By using common sense when building your links, you are making sure that Google will count in the backlinks to your website in all its algorithm updates in the future.