the main criteria we should follow is the quality of links on the page from which we want our link. For e.g. we want a link in free directory category, than we should see the listings over there, if it contains links to some web designing company or any hotel or link from any other category totally out of context, than its not a good place to get link from. These type of directories are junk and might also harm our ranking. We should avoid submitting our website to these type of directory.And what criteria do you use to determine if a directory is suitable or not?