I have an iPhone app that has over 3.5 million downloads and, from these downloads, have had over 225k people opt-in to receive emails from my company (our TOS allows us to send them any types of email... the only restriction is that it must come from me). So, my question is, how can I monetize this??? The users of my app are 60% female and 67% teenagers. Also, if you specialize in email monetization and would be willing to manage this list yourself, I'd be willing to work out some sort of agreement where you get X% of the profits as long as you make at least $X per month, or something like that. Thanks for your help!