Just to introduce you:
Exposure in magic refers to the practice of making magical methods ( the "secrets" ) available to those who are not magicians. It is generaly frowned upon as a type of spoiler that ruins the magical experiences for the audience.
Many videos can been seen either on the Tv or the Internet on exposure, many of them are made by Penn and Teller, as well as the Masked Magician who has generated a lot of controversy by exposing other people tricks.
Some exposure are done in the magician own right. Many magicians use false exposure to make people laugh and make them forget the sleight of hand behind the "magic". As an example, some magicians "reveal" the secret of linking ring saying that there is an hole, then he show the hole in the middle of the ring. Some created themself an effect, which is at their own right to expose or not.
My point of view
Some people have different argument about exposure, many of the "magicians" that agree exposure are most likely to be new magicians, most of them being teens, because they want to learn to do magic with a small budget. Exposure can be everywhere, it can be on your cereal box, as well as on a nice exposing website telling everything for free.
My point of view is that there is much more way to learn magic then by exposure, many of wich are targeted to people that want to learn magic, not to know the secret. There are more book in magic then in any other entertainment feild.
A magician called the "masked magician" argue that exposing old tricks make magician innove in new magic effects.
The process of creating a magic trick is much more harder then exposing a trick, I also think that instead of encouraging magician to create new stuff, it discourage them in the view of a future exposure. As well as there is so much magic effects out there that it is difficult to create something new.
Some magician likes to expose to make their spectator see the amount of skill needed behind the trick, so they can be seen as a skilled sleight of hander instead of self doing magic tricks.
Magic is all about having people think that what they seen is imposible, and has no logical way of doing this trick. The goal is to mesmerize the audience, if you convince them that all the magic tricks are "tricks" they wont belive in magic anymore.
In my opinion, learning from exposure, if you want to be a sucessfull magician isn't the best way. People that expose magic tricks dont cover any feild of entertainment, they only tell how the trick is done, and you are most likely to badly perform this trick because you dont know the subtlelity. I cant belive that with great magic books like Mark wilson complete course in magic, Wich cost peanuts! People still look around trying to find "free magic". The differance is there, take a look on youtube, there is so much exposure there that it make's me cry. When you see a video of someone doing magic, you can easily tell if this is a magician which learned from exposure or not.
If you want to learn magic for cheap, PLEASE! dont learn from exposing website, it will result on you badly performing a trick, and have everyone around get it. Just as an example, the Balducci levitation wich david blaine performed on Tv. Much people where mesmerized by that. Somewhere in the world someone has exposed this technique, and i think that everyone here know how it's done. Even my young cousin ( he is 6! ) know how it's done, he told me that if i was a good magician i could levitate like him

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So here some of good books you can buy, they are cheap, when you get them, you can truly say that you are learning magic.
Mark wilson complete course in magic. ( 17$ sold here and in a lot of library )
J.B bobo's modern coin magic ( 10$ Sold here, verry common book )
Royal road to card magic ( 11$ Sold here, hard to find in librarys... )
So with 38$ you get almost a complete course in magic, from beggining to intermediate level. With 38$! you can amaze people! what are you waiting for! drop your exposing website and buy this! There is so much material in these books that you will got material for a lifetime!
Also may i recommend you Maximum entertainment by Ken Weber. But its for the serious performer, if you are not expecting to perform for people dont buy this book, it's not in the cheap list to learn magic, its only a recomendation.
So that's one of my first "full lengh" essay, Hope you liked it.