hello friends i optimised meta tag but when do bookmarking then its meta data automatically not fetched.
About which meta tag you're talking to? description tag? Usually social bookmarking sites retrieve the data from the website content or left blank and we can fill it manually.
i guess you setup meta tags for keywords on your website. depending on how you are bookmarking, it may or may not fetch your meta data. if it doesn't, you will need to manually enter the meta data on the bookmarking sites.