LINK EXCHANGE PROGRAMAS
I mentioned earlier back links can improve page rank of a site in Google search result. Page rank of a website can be viewed through Google Toolbar. Link exchange with other website can give you some back links and some traffic. But extra care should be taken when you are participating in link exchange with others.
Goggle not counts every bank link of a site. They count only those back links that come from a quality and relevant website. Suppose you have a site on banking. If you get some back links from a music site those back links will not be counted. Because you are getting back links from a site that is not relevant to your site. So only links from a banking site will be counted for your banking site. Content quality of that site pointing back to your site also matters. If your site gets a lot of back links from low quality sites relevant to your content will not make any difference. So choose another site for link exchange carefully.
And also be careful for paid links. As search engines pay attention to back link when determining a sites page rank paid link may give a wrong assumption how popular a site is. So using paid link for a better position in search result is violation of Google's Webmaster guidelines.
Read what Google says about paid link.
Read my article about the future of backlink.