What is the important of the link exchange?

If we want to know about the important of the link exchange, at first, we need to know what is the link popularity. Link popularity refers to the number and quality of the incoming links that are pointing to your site. It's not just quantity.... its quality! So, page rank is not the last word, same category is also a big factor. Why?
Search engine optimization algorithm techniques depend on both theme based link and link popularity of the link page .If the link popularity of your site is increased, then your search engine ranking is also increase. You will want to approach established sites already listed in the search engines which have content related to your web site. These sites already have a steady stream of targeted visitors. More sites link to you, so more people will click-thru to your site. More visitors mean more sales of your product. You may have seen your total links counted on search engines. Search engines give preference to sites with high link popularity; better search engine rankings will result in more traffic .By Reciprocal link exchange you can increase your link popularity by theme based link and high page rank. One way link exchange (Triangular link exchange) is also a good way to increase your page rank. Our Search Engine Optimization techniques are made keeping in view Google SEO Guidelines.