Content Locking is a feature of OptinMonster in which you lock a segment of your content that becomes accessible by an action of user such as submitting email id or buying subscription. You can ask for filling a form submitting his or her email id or charge subscription once a user reads a particular percentage of post, say 30%. Once email id filled or payment made for the subscription, the user can continue with the rest of the content.
We do know that once we are in the midst of consumption process (be it consuming an orange juice or reading content), there is irresistible urge to complete it. So as per psychologists and economists, consumers will be ready to spend. That spending can be by agreeing to go for monthly/yearly subscription or agreeing to submit email id.
Content locking feature is great for growing your email list for email marketing. You have more segmented email list as you get to know the category and post/page for which the user opted to bypass the locked content.
If users are paying for information that has an element of competitive advantage when kept scarce, it is a win-win situation. The blogger/publisher/business marketer will work hard to come out with scarce information, and the one who will pay will benefit from the premium content/information.
For instance, an insider of property market can charge money from potential buyers for viewing the exclusive listing of properties put for sale. Content locking feature can be applied once user gets to know the geographical location of the property, but asked to subscribe for getting access to name, phone, and email id of the seller. If these listings are left open for free, sellers of the properties might get too many unsolicited calls/queries. Also, they may lose the privacy as many sellers do not want to disclose in open that they are in the process of selling their properties till the end. Since those who have paid the publisher of these listings must be serious contenders, end sellers need to deal with only buyers who are serious.
For those in the business of preparing research reports, content locking feature can help them monetize for the labor put in the process. This should not be considered as unethical as publishers spend considerable time and money on coming out with quality contents. Subscribers avail premium research reports without hiring a full time staff. So a win-win situation.