Snatching value is the game on the internet.

There are a parameter called Page rank which is a quality measure of the web content.

Appropriate links is a deciding factor in it.Thus there are active missions to earn links in different websites.
Link exchange is a popular method by which some of the webmasters manage to get a link, while there are others who buy a link,prices vary according to the page rank and i have sold one for $10, but i have heard that they are also sold for a price of $250 as well. There are further astronomical figures as well which are yet to be confirmed.

This page links contributing to better page rank and that leading to a better position on the search engine has been the cause for this unhealthy practice.

What is heard is that the page rank is divided into the number of links, i guess it includes internal and external within it and each of the links get a proportional share from it.This needs to be verified.

To improve the factors to better ranking article submission is considered a good practice and i happened to check freearticlesubmission.org, although it is with tld .org they are into stealing your page ranks.

This is how its registration is

As you can see above they are asking you to put a hyperlink of cheap hotels in your website which is less than 2 clicks in it.Its most likely that it is irrelevant to the topic.It appears to me more of stealthily taking away page rank than anything else.