26. A method of distributing, in a networked environment, an object that represents an advertisement, the method comprising: receiving a query from a user initiated at a computing device to create the object to represent the advertisement; creating the object to represent the advertisement to be made available for access in the networked environment, the object having metadata which specifies criteria of target recipients of the advertisement, the criteria being specified by the user; matching the criteria specified in the metadata of the object to users in the networked environment, to find recipients who satisfy the criteria; automatically sending the advertisement represented by the object to the recipients who satisfy the criteria; automatically generating multiple versions of the object to represent the advertisement based on an example object specified by the user; test-posting the multiple versions to compute price-performance attributes of each of the multiple versions.
26. A method of distributing, in a networked environment, an object that represents an advertisement, the method comprising: receiving a query from a user initiated at a computing device to create the object to represent the advertisement; creating the object to represent the advertisement to be made available for access in the networked environment, the object having metadata which specifies criteria of target recipients of the advertisement, the criteria being specified by the user; matching the criteria specified in the metadata of the object to users in the networked environment, to find recipients who satisfy the criteria; automatically sending the advertisement represented by the object to the recipients who satisfy the criteria; automatically generating multiple versions of the object to represent the advertisement based on an example object specified by the user; test-posting the multiple versions to compute price-performance attributes of each of the multiple versions. 29. The method of claim 26 , wherein the advertisement comprises, streaming media.