23. A method performed on a client computer system directly accessed by a user, the method comprising: i. obtaining at least preferences information of the user by monitoring online activities of the user, wherein the preferences information of the user is based on a history of the online activities of the user; ii. locally storing at least the obtained preferences information of the user in a local database located on the client computer system; iii. processing information received from the server after the user submits a query, wherein the information received from the server comprises search results responsive to the query submitted by the user and a plurality of advertisements related to the search results; iv. determining likely preferences of the user based, at least, on contents of the local database, wherein the determining is performed on the client computer system; v. selecting at least one of the plurality of advertisements for displaying to the user based on the determined likely preferences of the user, wherein the selection is performed on the client computer system; and vi. displaying the selected at least one advertisement to the user on a display device of the client computer system, wherein the preferences information of the user is not accessible to any other entity except for the client computer system; wherein the server comprises a search engine, wherein the query is a search engine query and wherein the information received from the server comprises search results responsive to the query submitted by the user and a plurality of advertisements related to the search results.
25. The method of claim 23 , further comprising appending local time information to the query to the server.