In the past, I talked about ways you can protect your eBooks when you sell information. One way is to use a password protected website to store your information. Another way is to use software to provide a lever of protection for your products. It is up to you to decide which strategy is best for you.
If you are looking for protection software, you can find it by searching Google for pdf protection or eBook protection. In my opinion, such software is very costly and not worth the expense. I believe a better approach is to simply sell as many copies of my eBook as I can rather than trying to figure out how I can stop the few people that will try and steal my products. My choice is to either focus my time on these thieves or focus my time on serving my customers. I believe delete PDF protection online that serving my customers is a better use of my time. Therefore, I believe the membership site option is the better approach.
One great approach that I use when I sell information is to sell eBooks at a set price, such as $27 and promote my $19.97 monthly audio membership to those buyers. Only customers for my eBooks learn about my audio club membership, therefore I know who is paying me. Another program that I offer is a gold membership. With this program, they pay a higher amount than the audio membership, which allows me to purchase my membership software, known as AMember. AMember allows me to track user names and passwords for my customers so I can limit access to only my authorized members.
As far as how I handle protection for a $27 eBook, I do not worry about it. Security is not a major issue with that type of product. My approach is to just let people know that the eBook is not free and if they did not buy it they should delete it.
As far as my audio club or membership site the security is built in to my membership program. Because it is a continuous expense, or even if instead I made it like a physical or digital product protected by my membership site, I now have the ability to decide who can access it. This is why I recommend membership site software as opposed to eBook protection software.