From sales: Someone who will call, email, text, and then call again to determine the parameters of your product or service, only to pick it apart, find the problems and challenges with it, and even go as far as find online complaints about you, your product, or your service...all the while never really intending to close real business with you.
This individual will likely want to schedule conference calls, meetings, or other circle jerk media to ensure even MORE of their friends can hear or see you flop around on the pier like a fish out of water.
Best strategy - DELETE BUTTON!!!
"Hey Tim - Mrs. Jones just called..." "Yeah - I know - she's a total timethief"
See also: time waster, schlub, schmuck, poor execution