Vendor Membership add-on will allow for utilization of the Magento recurring profiles in conjunction with vendor registration of Microsite Pro add-on (which is required for Vendor Membership add-on).
Virtual products have to be created with recurring profile. Each product will reflect vendor membership payment schedule and price. More details regarding Magento Recurring Profiles functionality can found here: http://docs.magento.com/m1/ce/user_guide/catalog/product-recurring-profile.html.
Once virtual products with recurring profile are ready, membership levels can be created in Configuration > Vendor Membership > General > Membership Types
Here membership levels can be added, code setup, title, sort order and in
Product SKU column set SKU of recently created virtual product with recurring profile setup. Limitation to the membership can be added on how many products vendor allowed to create within that membership level.
Currently the only supported payment method for Vendor Membership add-on is PayPal express. Similar to the limitation in Magento for recurring profile products. More details on how to setup PayPal in Magento can be found here: http://docs.magento.com/m1/ce/user_guide/payment/paypal-express-checkout-intro.html.
Vendor registration is very similar to the one in Microsite Pro add-on. In addition vendor will be presented with an option to select membership level. After filling registration form and selecting membership level, vendor will be redirected to PayPal express page to confirm subscription agreement and then to registration confirmation page. If subscription was successful vendor will be able to login to vendor portal and start to create products and accept orders. Vendor account is synchronized with recurring profile, i.e. if profile was suspended vendor account will be suspended too and all products will become suspended (will be removed from frontend) and vendor will stop to receive orders.