Free-for-all links list, where there are no qualifications for adding a link.
FFA pages are nothing more than raw link pages. They often have no categorization, no review… and no traffic. On the plus side, many do offer marketers the gratification of instant submission — something not found easily elsewhere — although the gratification does not last long.
The link pages are often powered by an FFA script. The script automates the addition of new links and the deletion of old links once a limit has been reached. Automated submission scripts exist, too. The submission scripts and the processing scripts keep each other busy with minimal human intervention of any kind.
FFAs constitute most of the “search engines” and “directories” on products designed to “submit your site to thousands of search engines and directories.” While this sounds like a potentially good source of visitors, the reality is that these sites get very little worthwhile traffic, and their benefits in terms of link popularity may be overstated.
(Note: of all the sites in the Google category for FFA, only a few have any Page Rank. Update: the category appears to have been deleted from the directory.)