11. A non-transitory computer-readable media that stores instructions, which when executed by a machine, cause the machine to perform operations comprising: recommending hash tags to a user who is generating a new comment to be posted in an Internet web site, the hash tags recommended based on concept information included in the new comment, the concept information determined by a concept server computing system based on content of the new comment, the recommended hash tags previously stored in a hash tag database and generated by analyzing a plurality of existing comments, wherein the recommending includes: determining if a link is included in the new comment, in response to determining that a link is included in the new comment, extracting content that is referenced by the link, and determining the concept information from the extracted content; presenting to the user the recommended hash tags in a prioritized order determined based on how recently the hash tags have been used in other posted comments and a maximum reach and impact of adding the hash tags to the new comment; providing a user interface to enable the user to select the recommended hash tags; and publishing the new comment with the hash tags that are selected by the user.
11. A non-transitory computer-readable media that stores instructions, which when executed by a machine, cause the machine to perform operations comprising: recommending hash tags to a user who is generating a new comment to be posted in an Internet web site, the hash tags recommended based on concept information included in the new comment, the concept information determined by a concept server computing system based on content of the new comment, the recommended hash tags previously stored in a hash tag database and generated by analyzing a plurality of existing comments, wherein the recommending includes: determining if a link is included in the new comment, in response to determining that a link is included in the new comment, extracting content that is referenced by the link, and determining the concept information from the extracted content; presenting to the user the recommended hash tags in a prioritized order determined based on how recently the hash tags have been used in other posted comments and a maximum reach and impact of adding the hash tags to the new comment; providing a user interface to enable the user to select the recommended hash tags; and publishing the new comment with the hash tags that are selected by the user. 14. The non-transitory computer-readable media of claim 11 , wherein the hash tags that are recommended to the user are accessed from a hash tag database which is configured to store a plurality of hash tags along with their corresponding concept information, and wherein the concept information included in the new comment is matched with the concept information stored in the hash tag database.