Ask any magician who does magic for a living and they will say 99% of the time that they have learned more from books then they have from DVD's.
Maybe so, but ironically enough one of the best authors of one of the best magazines/books to ever be printed (The Magic Menu) states: "DVD is really the best choice for magic instructional media -Jim Sisti." I think saying "99%" is a little far-fetched, and an inaccurate percentage, especially these days. The reason being is, not as many even bother reading books to begin with, as they wish to take every shortcut possible.
Now back about 20 years ago, maybe 99% would be more accurate, as DVDs were not available. Granted I am also from the old school of "book learners," but I see DVDs as a great new learning tool for those who choose to supplement them in with their reading, as opposed to replacing books entirely. After 26 years of magic thus far, I do not have that many DVDs—I only have some of the classic sets. However so far I have thoroughly enjoyed what I have watched, and actually was able to grasp the information a lot quicker by actually seeing it done live by a performer.
With books, some may miss key elements as far as timing and misdirection goes. But like I also said, I was already well grounded in magic long before I even seen a DVD. So my prior knowledge helped me to learn much more quickly. I think DVDs are a great new learning tool as long as they are used for the right reasons. Not simply because one is too lazy to read, or is looking for instant gratification. DVDS should be used to "fill in the gaps" so to speak, not replace books.
They provide a great visual reference, and allow another magician to come into your home for personal instruction. Some older magicians tend to become jaded, and antiquated in their own solidified and outdated ways. They refuse to evolutionize simply because they fear something new, or hold resentment because this was not available for them when they were first learning, so why should everyone else be able to just jump in and freely access all the knowledge that they had to spend years reading?
I felt the same way, and still do to a point. I believe beginners should also go the book route for starters, as books provide far more material for a much better price. I think that if one sticks to only DVDs, they are actually cheating themselves out of a lot of knowledge, a lot more that could ever be found on DVDs. So build your foundation with books, and supplement it with DVDs from time to time.
Just make smart, and wise decisions. Beware of high priced i"ndividual effects" as well, and only buy what gives you the most bang for your buck. This is why I only stick to the "classic sets."