Locking References in Wisdom

It would be very cool if there was a way to allow free access to Wisdom, but if a user tries to click on the video references it shows the videos as locked and then takes them to a signup screen for them to purchase access to a Hub. Another way of doing it might be to allow a user to have 3-5 free Wisdom searches per day, at which point it redirects them to a page where they can sign up for the hub that the content is pulled from.