This may be known to you. Still I know it first time. Google.com has the following statistics - In DMOZ ------------------- 560 listings In Yahoo directory --------- 78 listings del.icio.us bookmarks------ 29,284 Following is more surprising - Meta Description: missing Meta Keywords: missing
Yeah - It's not necessary . People do it to boost up their site for specific keywords . Infect if you notice Digg dot com doesn't have a robot.txt .. so what you will guess from it ?
bothe Meta Description, Meta Keywords no need now . SE not considering metatag bcz of spamming. Only meta description will show in SERP with the title