There are a lot of scenarios in which a membership site would benefit from using a WP Multisite install. Sometimes administrators want to allow members to create their own child sites within the same WordPress installation, while other times it’s beneficial to allow users to share an account among child sites. For example, take this scenario that a site administrator laid out for a project:
I’d like users to be able to sign up for one account, then have access to content on all child sites. For example, if they sign up for a tutorials account, they have access to a child site devoted to guitar tutorials (with different access levels for tutorial types – beginner, advanced, etc). Then they can purchase access to other child sites, such as piano tutorials, though I’d like the option to allow same access rules to apply to all of the child sites (i.e., for selling access as a beginner “bundle”).
There are a lot of interesting setups that you can use with a membership plugin for WordPress multisite, but finding the exact functionality you want can be challenging. There three major membership plugins that provide full multisite support: Memberships by WPMUdev, Paid Memberships Pro, and S2Member Pro. All of them have been around for quite some time (Membership is the newest, yet was launched in 2010), so they’ve matured and had time to work out kinks in multisite support. They could also serve as a starting point for a customized solution.
Memberships by WPMUdev
Memberships allows users to create child sites by signing up for your membership – the flagship example for this is Edublogs.org. You can charge members for access to their own child site, or allow members to create sites for free, then charge for other access rules. You could also create a paid social network, as Memberships supports BuddyPress.
As for user accounts across all child sites, I couldn’t find concrete help on this (I haven’t used Memberships myself). I do think you could allow access to child sites based on a customer account at the parent site based on this thread. Looks like it may take a very slight amount of tweaking, but will be able to achieve this structure.
The plugin is $19, and support / updates are included in the plugin purchase for one month (you’ll need a WPMUdev membership for more support).
Paid Memberships Pro
Paid Memberships Pro is free (we have a full review of Paid Memberships Pro for more info), and while it doesn’t support multisite in the core plugin, there are add-ons to make PMPro multisite compatible.
The Network Membership add-on allows restriction for an account across child sites, which allows user to share credentials among your child sites. If you want to allow users to create their own child sites or blogs, then you’ll want to check out the Network/Multisite Membership add-on.
While add-ons are free, support is not included with add-ons or the core plugin, but is available for $97 per year.
To the best of my knowledge, S2Member Pro probably won’t work for users that want to share one user account across multiple child sites, as it requires a separate installation on each child site. This item from their specs page provides more detail on this:
Compatible with WordPress Multisite Networking (optional). *Note: Users/Members are NOT shared across the Network. Each child blog or sub-site in a Network runs its own instance of s2Member.
However, S2Member can allow members to create their own child sites or blogs. You can control the number of child-sites created by each user, and you can limit access to child sites for each account. For example, you could allow free users to have access to your parent site, but only allow paid users to create a child site or blog. S2Member Pro also fully supports BuddyPress and bbPress.
S2Member requires a one-time purchase of $129 for an unlimited license to be used on a multisite install, and includes updates and support for life.
Of these three, Paid Memberships Pro is my favorite to work with, as you’ll probably need support or will be working with a developer anyway for a setup like this, and it’s very extensible and flexible. Site administration and usage with the plugin (i.e., setting up dripping with the series add-on) is fairly easy as well.
There are other platforms that are working on this currently (such as WooCommerce, MemberMouse, and MemberPress – aff links), but I don’t believe any of them have the multisite compatibility fully ready to go yet. MemberMouse has said they’re working on this still (we have a full review on this as well), I know WooCommerce has a multisite-plugin on the roadmap, and the grapevine says that MemberPress is working on this, too.
Want to read more about Multisite? Checkout this full guide from Mashable.