In response to the Do Tags Work? article by Cathy Marshall, Leslie Orchard, who used to work for Delicious, wrote why he believes tags do work. My first thought when reading Cathy's article was that Flickr seems to be a bad subject for testing the usefulness of tagging, since Flickr doesn't require the use of tags. For this reason, Leslie says that users are more likely to write good titles and/or descriptions of their photos, leaving tagging as only an afterthought. The tools used to bookmark pages in Delicious however, automatically fill in the page titles and descriptions (using selected text, if any) often leaving tags as the only user-generated input. Perhaps tags are only useful for certain types of content.