it would be ideal to have unique articles submitted to article directories. however, if you submit to lot of directories, its hard to get all those unique articles. google has duplicate content penalty which you dont want to get. best way to get around this is to make a game plan. decide how many article directories you are gonna submit to. for example, if you submit to 50 directories, then i would suggest to get atleast 5 unique articles and then spin them using an article spinner to make them look like unique. you will be able to avoid the dup penalty this way