In a similar process ( but not only focused on marketing) I did a consulting job for a startup ( mostly focused on concept and social design) and joined the team after some time.
The basic thing is you can't be 100% sure, it won't work without some trust. I get shares depending on the success, first 7% after relaunch, next 5 % after 10.000 user and so on I think something like this might work in your case...
The basic thing is you can't be 100% sure, it won't work without some trust. I get shares depending on the success, first 7% after relaunch, next 5 % after 10.000 user and so on I think something like this might work in your case...