You can even check in Analytics with Advanced Segment: Direct Traffic and you will find Slurp counts as direct traffic or direct visitor.
Look at this:
188.8.131.52 - - [25/Nov/2012:13:26:06 -0500] "GET /texas/widget.html HTTP/1.1" 200 5978 "-" "Mozilla/5.0 (compatible; Yahoo! Slurp/3.0; [help.yahoo.com...]
and every time Slurp appears in my logs it is followed by the Mediapartners bot:
184.108.40.206 - - [25/Nov/2012:13:26:07 -0500] "GET /texas/widget.html HTTP/1.1" 200 5978 "-" "Mediapartners-Google"