if you were a sales promoter you would have no customers. to attract investors or even some curious person who wants to ask questions and possibly change your mind and be your partner, you need to expose your product: what you are offering, what people who are your partner will win ... but if you keep it a secret of this essential information and still oblige people to contact you to get more information so you’re not interested in partnering, at least you’re not showing interest
There are very sensitive ways to make money. I don't have to say it's above this one. If someone really wants to collaborate and make money in the long run, they won't save time talking to me privately. If they're interested in their work, then get started. If not, you can go out