I use to do some day trading. The joke among the day trading community in those days was that if Kramer recommends buying into a company, then usually a good idea to do the opposite.
That's probably true due to the size of his megaphone. Even if all his advice was great, his recommending a stock could quickly drive the price up to where it wasn't great anymore.
No, his secret is that he'll praise a stock one week and pan it the next (or vice versa) so that he can cherry pick his 'wins' later.