Is it possible to get a celebrity to endorse your start-up without upfront compensation and without guarantee of future compensation? I am not talking about doing any sort of work. I'm talking about only a written consent to support the product that I could use when I speak with potential investors. Something that says "I like the product and if it is ever sold, I will publicly support it in return for the royalty", but take nothing upfront. Or is this not possible?
By the way, I wrote an email to a contact for one celebrity and never heard back. Wondering if they ever got the email and are not interested, or they never got it. Should I try to contact them again?
EDIT: Please, don't reply to me about how ineffective endorsements are. The point is not PR to the masses at this moment. The point is finding early customers who ARE celebrities.