23. A method of distributing, in a networked environment, an object that represents an advertisement, the method comprising: 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; matching the criteria specified in the metadata of the object to users in the networked environment, to find recipients who satisfy the criteria; sending the advertisement represented by the object to the recipients who satisfy the criteria; test-posting multiple versions of the object to represent the advertisement, to compute price-performance attributes of each of the multiple versions.
26. The method of claim 23 , wherein the advertisement comprises, streaming media.