an idea about sires

[Danzig]

just had a thought, while reading an article about kip deville going to the japan cup.

has anyone in the breeding business considered supplementing a good runner so that said runner will continue to race, which has to be the best type of advertising for a sire already in the shed?

kiplings best progeny is kip deville, other than him kipling hasn't sired much at all. so i would think it's in kiplings (and his stud farms) best interest to keep kip deville on the track.
so, take street boss for instance-what if darley was to supplement a horses racing career so that he'll keep running (and presumably winning) so that he and others by street cry would offer up a huge racing resume for their old man-would this be feasible? now, obviously a stud farm can't offer up the 10k stud fee x's 100 to pay off an owner, but wouldn't assumed purse winnings along with some green from a farm be enough to encourage an owner to perhaps attempt to keep a horse in training at four?
or is this idea not feasible at all?
it just seems that in the 'good old days' that a farm would run the offspring of their big sire, so as to prove their sire had the goods, and to draw more mares to the sire. of course now it's turned into winning a few races so you can try to make a sire out of the sons of a sire. of course, times have changed with commercial operations-but wouldn't it also be in a farms best interest to keep top colts on the track?? then they don't have as much competition for their sires line.
or is this just a waste of thought??