The revenue share model is going to be your best bet until you are capable of determining your lifetime value for a user. It is rather impossible to speculate

The revenue share model is going to be your best bet until you are capable of determining your lifetime value for a user. It is rather impossible to speculate without knowing the niche and the price point for someone to subscribe. Even then things such as conversion rates, landing page sign up process, and website copy all have influence on whether a campaign is going to be profitable (read: worth the time) of a proper affiliate marketer. It can be somewhat tenuous going down this route before ever even doing in house testing so my advice would be to start there first before approaching affiliates/networks if you are serious about going down this route and succeeding.