Abstract: Advertisements of various time lengths, preferably consumer tailored, are pre-cached on consumer client systems of a streaming program. Selected ones of advertisements are synchronously rendered at advertisement time slots of the streaming program, effectively substituting or replacing advertisements, if any, included with the streaming program for the advertisement time slots. In various embodiments, the advertisements are downloaded to the client systems in an adaptive manner, such that the downloads are substantially non-interfering to the receipt and rendering of the streaming program.