If you are going to sell your ebooks online, then you need to know how to protect your PDF files. Unfortunately, there are people out there who will take any opportunity to get a free copy of your book.
You need to accept the fact that no matter how good your security, and no matter how careful you are, some people WILL steal your product. Your job as an ebook publisher isn't to stop 100% of theft. It's to stop the majority.
Trying to stop all ebook theft is not only very difficult, it's a poor use of your time. Once you realize that stopping 99% is good enough, you can take the appropriate measures and move on to using your time more productively. As for that other 1%? Well, good for them: if they want to spend their time and energy into stealing (because that is what it is), at least you aren't going to make it easy for them. And who knows, perhaps Karma really exisits? Let's hope so ;-)
This will not stop theft. However, it will make life a lot easier if you ever have to follow up on blatant theft or plagarism. One common scenario, is a webmaster getting hold of a copy of your ebook, and selling it themselves. Don't think this doesn't happen: it does, and I have talked with people who have been on the receiving end of it.
If you find someone has stolen content from your ebook, then be prepared to file a DCMA complaint. You will have to have cast iron proof that you are the original author, along with proof that you published it first.
This is your next step, making sure your PDF isn't indexed by Search Engines. A PDF file can be indexed just the same way a webpage is, so there is no need to input the meta data...that is helpful for the Search Engines to find your PDF, which you don't want to happen. Also, make sure you zip the PDF, don't just upload it to your server. A zip file protects the content inside from being indexed.
Some publishers will want to take extra measures, such as password protecting the ebook, and giving out the password on the download page. I personally don't do this, as I feel having to input a password each time you view a PDF is annoying. However, it does have the advantage that if a copy of the PDF falls into the wrong hands, they will have trouble opening it. If you decide to password protect, then use at least 128 bit encryption, don't waste your time with less than that.
Using a noindex nofollow meta tag just isn't enough. Sorry, but it won't stop all Search Engines from indexing the page. By all means, use the tag. Just don't expect it to give you 100% security.
Make sure you choose an unguessable name for the download page. thank-you.html or something similar is just asking for trouble.
Do not put text on your page that people will search for. The common search phrases used by people looking for free products are ones like "thank you+download", paypal+receipt" "thank you for your purchase" etc etc
They take advantage of the fact that you must display this type of text to conform with Clickbank and Paypal rules. So, the simple answer is...don't put this information as plain text. Put the text like that into an image (with no alt tags). Customers can still read it, but Search Engines can't.
An example of a text image that I use on one of my download pages is shown below.
This is probably one of the easiest ways to secure your e product from unathorized download. At only $5 a month,(the starter plan, which allows you up to 10 products) it's a cheap way to stop almost all theft of your ebook.
One of the features I find to be particularly useful, is their expirable download links. Each purchaser of your product gets a unique download link, that will only work a certain number of times, and then it expires. So if the link gets posted on a forum, shared on Facebook or whatever, then you don't have to worry. Read about the ejunkie features on their website.
Successful-Ebook-Publishing.Com reviews: these are my personal opinions, and have been given in good faith that all information is correct. All reviews have been made with personal experience with the product. While I make every effort to be current, accurate and factual in my reviews, I cannot guarantee that a product performs as stated.