Explorer and “marketer” Sir Ernest Henry Shackleton, led four Antarctic expeditions; traveling the furthest south of any human during his voyage aboard the Nimrod.

How did he round up his crew? He advertised for what he did NOT want:

“Men wanted for hazardous journey. Small wages, bitter cold, long months of complete darkness, constant danger. Safe return doubtful. Honor and recognition in case of success.”

Translation: No wimps – and you’ll probably die!

Market to the target market that has the clients you want, and discourage those prospects who will only end up being ‘tire kickers’ and time wasters.