Well, for start - be sure you give it to people you know or work with for some time. Do not give it to a strangers you don't know how serious they are. Also, give it to those who need it for reaching leaders position or those who work hard.
If you made a mistake and send it to someone who is not serious in business all you can do is to push him/her to use it by sending sfi messages, e-mails and, if you know them - call them.
this is all you can do.
