This is the most valuable plugin I have ever bought!
And don't speak about the price!
You have no idea how much it increased my earnings!
This is a must have, for every Wordpress install.
You owe it to yourself! If you don't buy it, you lose BIG TIME!
The Social Locker plugin is the best one, and it really expands the readership. It offers many functions, it is easy to configure. The most important thing is to use it wisely, and then the readership around the site will grow every day.