The biggest result from fitness videos come from consistently doing them. The type of video is very secondary to how often it is done. Fitness videos you purchase are frozen in time. No new information is put into them, and you get stale. You can find current, up to date fresh videos that are just as effective, more interesting, and free.
The great thing about exercise is the fact that it doesn't really matter what you are doing, as long as you are doing it on a regular basis. Yes, you may need to make proper selections if you're seeking a specific goal, but I can tell you this much: There are a lot of free videos on on-line to use. The great thing about them is the fact that they are just as good as the ones you buy, but they are free.
Yes, free fitness program videos that are available online are as good as those programs that you purchase at the store, because the ones online are posted by people who are just as knowledgeable, they just have different reasons for posting for free rather than for profit. For example, they might just want exposure, rather than pay.
I'm fine if someone is trying to save money and refuses to buy expensive fitness programs, however the quality of programs like the P90X and others is going to be much higher and focused to your needs. It all depends how serious you are and what your goals are but there is no way the free content equals the expensive fitness programs.