curlybracket

This WordPress plugin restricts non-authenticated users to a number of pages to view. You can define how many pages an unauthenticated user may view. If the limit is reached, the user is redirected to the WordPress login page (default) or a page of your choice.
This plugin uses cookies, but not only. People can not just empty their cookies and start watching your page again. In this plugin i use a technique in which I combine a users’ IP address with the user agent of this particular user, and create a more or less unique hash out of these two informations. This hash is stored as a file in the wp-content/uploads directory.
A site administrator can choose to reinitialize all sessions and empty the hash files.
Furthermore, robots might be blocked. However, important bots like GoogleBot, BingBot and YahooBot are excluded from the restriction.
This technique might be problematic for users using Tor / TorBrowserBundle as lots of people share a same originating IP address and also the same user agent (check here https://panopticlick.eff.org/). I will certainly test this aspect a little better in a later version of this plugin.

Pageview content restriction

Restricts access to your Wordpress site after a certain number of pageviews.

Imprevo

This plugin restricts access to default and custom post types based on user roles. The plugin displays a custom message to those who do not have access to view the content.
For reporting bugs, getting support or feature suggestion, please click the link below: 
http://www.imprevo.net/

Role Content Restriction

Restricts access to selected post types based on user roles.

Pageview content restriction vs Role Content Restriction