EXHIBIT 2

JOINT FILING AGREEMENT

The undersigned hereby agree to the joint filing of the Amendment No. 7 to Schedule 13D to which this Agreement is attached.

Dated: March 3, 2014

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