Web 2.0 blog link building is very popular now days. Reputation of these sites have been increasing for sharing content, video, audio or connecting with your friends. These websites offer different way of sharing your content like video, audio, files and blog post. There is no limit on the content you have been sharing on these sites like that of article directories. So you have absolute freedom of content you want to share on these sites. You can use these sites to produce back links for your website which get approved very rapidly. Whatever you would share on these sites would get published instantly so you wouldn't require to worry about its indexing and approval. This way, use of web 2.0 sites is a good way to build links for gaining higher ranking. One more advantage is that, in some sites you can customize the design of your space. So you can choose the color and theme which is appropriate for your main website design.