SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Empire Capital Management, L.L.C. (Last) (First) (Middle) 1 GORHAM ISLAND SUITE 201 (Street) WESTPORT CT 06880 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol KEYNOTE SYSTEMS INC [ KEYN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 05/20/2013
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/20/2013		S		364,594	D	$12.78	2,200,000	I	See notes(1)(2)(3)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* Empire Capital Management, L.L.C. (Last) (First) (Middle) 1 GORHAM ISLAND SUITE 201 (Street) WESTPORT CT 06880 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Empire GP, LLC (Last) (First) (Middle) 1 GORHAM ISLAND SUITE 201 (Street) WESTPORT CT 06880 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Empire Capital Partners, L.P. (Last) (First) (Middle) 1 GORHAM ISLAND SUITE 201 (Street) WESTPORT CT 06880 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Fine Scott A (Last) (First) (Middle) C/O EMPIRE CAPITAL MANAGEMENT LLC 1 GORHAM ISLAND, SUITE 201 (Street) WESTPORT CT 06880 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Richards Peter J (Last) (First) (Middle) C/O EMPIRE CAPITAL MANAGEMENT LLC 1 GORHAM ISLAND, SUITE 201 (Street) WESTPORT CT 06880 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. This statment is filed by (i) Empire Capital Management, L.L.C., a Delaware limited liability company ("Empire Management") with respect to the shares of Common Stock directly held by Empire Capital Partners, L.P. ("Empire Onshore"), Empire Capital Partners, Ltd. ("Empire Offshore"), Empire Capital Partners Enhanced Master Fund, Ltd. ("Empire Enhanced Master," and together with Empire Onshore and Empire Offshore, the "Empire Investment Funds") and Charter Oak Partners, L.P. and Charter Oak Partners II, L.P., which are discretionally managed by Empire Management (together, the "Empire Sub-Advised Funds"); (continued in footnote 2)

2. (continued from footnote 1) (ii) Empire Onshore with respect to the shares of Common Stock directly held by it; (iii) Empire GP, L.L.C. with respect to the shares of Common Stock held directly by Empire Onshore; (iv) Mr. Scott A. Fine ("Mr. Fine") with respect to the shares of Common Stock directly held by the Empire Investment Funds and the Empire Sub-Advised Funds and (v) Peter J. Richards ("Mr. Richards") with respect to the shares of Common Stock directly held by the Empire Investment Funds and the Empire Sub-Advised Funds.

3. Empire Management serves as the investment manager to, and has discretion over the securities held by, the Empire Investment Funds and the Empire Sub-Advised Funds. Empire GP, L.L.C. serves as general partner to Empire Onshore. Empire GP, L.L.C. has retained Empire Management to serve as investment manager to Empire Onshore. Mr. Fine and Mr. Richards are the only managing members of Empire Management and the only two managing partners of Empire GP, L.L.C. Mr. Fine and Mr. Richards each disclaim beneficial ownership of the securities in this filing, except with respect to any pecuniary interest in such securities.

Remarks:

	/s/ Scott A. Fine, as Managing Member of Empire Capital Management, LLC /s/ Peter J. Richards, as Managing Member of Empire Capital Management, LLC	05/22/2013
	Scott A Fine & Peter J Richards, as Managing Partners of Empire GP, LLC	05/22/2013
	Scott A Fine & Peter J Richards, as Managing Partners of Empire GP, LLC as general partner to Empire Onshore	05/22/2013
	Scott A Fine	05/22/2013
	Peter J Richards	05/22/2013
	** Signature of Reporting Person	Date
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