One thing I would like to see is the ability for a Provider to email all it's subscribers for important updates. Right now, there's no way to email all subscribers to inform them about imp. events. I believe this would drive more sales, user interaction and keep the customers up-to-date. Thanks!
Actually we added subscriptions to profile, so if someone subscribes to vendor's profile and vendor publish post or new product then there will be notification for all subscribers.
Lot of good ideas there but I really liked the "Feedback Request Notifications" feature :)