User blog comment:Big Lupu/Why do wards take slots?/@comment-4652200-20130608202353/@comment-6281755-20130610003708

Exhaust destroys ADCs damage output to about 40% from normal(if spells not used, its even 35%). Because of the slow, ADC usualy has to re-position, and as most know, you can't AA and run at the same time, reducing damage output even more. Priceless.