EX-3 4 ex3.htm EXHIBIT 3 ex3.htm
EXHIBIT 3
 
JOINT FILING AGREEMENT
 
The undersigned hereby agree to the joint filing of Amendment No. 2 to the Schedule 13D to which this Agreement is attached.
 
Dated:  April 30, 2013
 
 
DISCOVERY GROUP I, LLC
for itself and as general partner of
DISCOVERY EQUITY PARTNERS, L.P.
     
     
  By Michael R. Murphy*
    Michael R. Murphy
    Managing Member
     
     
  Daniel J. Donoghue*
  Daniel J. Donoghue
   
   
  Michael R. Murphy*
  Michael R. Murphy
 
 
  *By:  /s/ Mark Buckley
    Mark Buckley
    Attorney-in-Fact for Daniel J. Donoghue
    Attorney-in-Fact for Michael R. Murphy