Vincent,
There are probably several ways to do this, the question is what is best for what you want to do.
If you want the content to show up on the same page, based on registration date, use something like this:
<?php if(S2MEMBER_CURRENT_USER_PAID_REGISTRATION_DAYS >= 30){ ?>
Put your drip content to Members that started paying you at least 30 days ago here.
<?php } ?>
<?php if(S2MEMBER_CURRENT_USER_PAID_REGISTRATION_DAYS >= 60){ ?>
Put your drip content to Members that started paying you at least 60 days ago here.
<?php } ?>
<?php if(S2MEMBER_CURRENT_USER_PAID_REGISTRATION_DAYS >= 90){ ?>
Put your drip content to Members that started paying you at least 90 days ago here.
<?php } ?>
You will need to enable a php plugin such as this one: http://wordpress.org/extend/plugins/php-execution-plugin/
Also, if you want newer content to show on the top each time, just reverse the order.
If you wanted to do this with different pages, then you just add the correct code to each page.
However, You would have to have some page that also drips links to the new pages like so:
<?php if(S2MEMBER_CURRENT_USER_PAID_REGISTRATION_DAYS >= 30){ ?>
<a href="content-drip-30-days">View Newest Content Here</a>
<?php } ?>
Unless you can hook into the menu and add new content pages dynamically…
Hope that makes sense.
Dave