Opt-In Panda for WordPress
This is a content locker plugin which will hide or blur certain part of your content and allow access only when you users subscribes to your mail list by providing the email ID. Now, this can be a great option if you are offering something for free or offering any downloading link but may not work for general blogs.
This plugin works perfectly with the prominent email newsletter services like MailChimp, Aweber, GetReponse. So, you can give it a try.
Price: $23 – Free Version https://wordpress.org/plugins/opt-in-panda/
Opt-In Panda Main Features: