Budget Reallocation Practice 2009 enroll Cost per enroll Budget Direct mail 30 $1,070 $32,100 E-mail 12 $125 $1,500 Display advertising 73 $1,370 $100,010 Paid search 36 $833 $29,988 Total 15 1 $ 163,5 98 i i Page 10 Previous slide What if HBS sets Direct Mail to zero and recruit the missing 30 enrollees by increasing investment in the next least expensive substitute medium