This seems to be yet another variation of the classic, mistaken belief that "your attention is so important that strangers will pay money to send you mail" [0].
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I think: 1. Whether something is valuable can only be discovered if you try to set a price and sell it. Until then, you can not know. 2. LinkedIn has big part of it's business selling 'InMail' at around 2$ per piece. So clearly some people's attention is so important that strangers do pay money to send them mail.