the software does queries based on keywords they want, runs them through google, extracts the domains, does a whois, tries to grab the contact info and the email address and sends out the link request.
Basically, its no work for them, it generates an FFA link page for them that never will get any traffic and they sucker people into giving them return links.
Based on how many of these you get, you can get a rough idea how well you show up in the search engines.
