To whom it may concern,
I have a couple of suggestions.
1. Please, can you add GoCardless as a payment option, you can take one off payments with it but it is also great for subscription services as it is a direct debit system. It would be ideal for prosite subscriptions and memberships as well as selling individual products on marketpress. At 1% with a max charge of £2, it is also much cheaper than paypal etc. https://gocardless.com/
2. Please, can you look at integrating some of the Zoho products? They have some that are similar to other integrations such as mail campagins but it would also be useful to integrate with their CRM. I know they are open to integrating with you. https://www.zoho.com/