I think you would need to present an excellent explanation of Eager Zebra games first, then include info the gift cards.
This advertising might be best presented to your warm market as once they become PRMs, TripleClicks takes care of motivating/advertising to them for us.
Your warm market you can explain to face to face, then send email with the e-connection for the gift card. Or, get physical cards, some people might prefer this.
