i have heard somewhere that getting backlinks from web 2.0 sites is bad idea..........but in link wheel techniques ..we have used web 2.0 sites .......then what is right way
I don't think backlinks from web 2.0 is bad. The links may not have a good effect in highly competitive niches. It certainly isn't bad. But in low competition niches it can make an influence.
A link is a link. It depends on the value it delivers. If the particular Web 2.0 site is managed well with high quality and high authority, the back links will certainly plays important role in your SEO. Even if the static pages which is not Web 2.0 that is poor in SEO score and low authority will not deliver the back links value. So, it is depending on the page score and not on web 2.0.
Link to a quality site is the most important thing for the link not the platform of the site. web 2.0 is working fine for me.