EX-10.1 FOURTH AMENDMENT TO LEASE

Exhibit 10.1

FOURTH AMENDMENT TO LEASE

FOURTH AMENDMENT TO LEASE dated as of this 26th day of November, 2007 (the “Effective Date”) by and between BOSTON PROPERTIES LIMITED PARTNERSHIP, a Delaware limited partnership, the general partner of which is Boston Properties, Inc., a Delaware corporation, as landlord (“ Landlord ”) and CONSTANT CONTACT, INC., a Delaware corporation, as tenant (“ Tenant ”).

RECITALS

     By Lease dated July 9, 2002 (the “ Original Lease ”), as amended by First Amendment to Lease dated as of June 29, 2005 (the “ First Amendment ”), Second Amendment to Lease dated as of July 24, 2006 (the “ Second Amendment ”) and Third Amendment to Lease dated as of February 27, 2007 (the “ Third Amendment ”) (the Original Lease, as amended by the First Amendment, the Second Amendment and the Third Amendment, is hereinafter referred to as the “Lease”), Landlord did lease to Tenant and Tenant did hire and lease from Landlord certain premises containing 50,705 square feet of rentable floor area (“ Rentable Floor Area of Existing Premises ”) located on the third (3rd) floor in the building (the “ Building ”) commonly known as Reservoir Place Main (formerly referred to in the Lease as “ Reservoir Place II ”) at 1601 Trapelo Road, Waltham, Massachusetts (referred to in the Lease as the “Premises” or “Tenant’s Space”, hereinafter, the “ Existing Premises ”). The parties further acknowledge that the term has not yet commenced with respect to a portion of the Existing Premises (i.e., the “Expansion Premises”, as such term is defined in the Second Amendment), and that Tenant is currently subleasing such space pursuant to a separate sublease agreement.

     Tenant has determined to lease from Landlord an additional 28,252 feet of rentable floor area (“ Rentable Floor Area of Fourth Expansion Premises ”) on the third (3rd) floor of the Building (the “ Fourth Expansion Premises ”) shown on Exhibit A attached hereto, upon the terms and conditions contained in this Fourth Amendment to Lease (the “ Fourth Amendment ”). The Fourth Expansion Premises is comprised of the “ Fourth Expansion Premises A ”, which is 25,661 feet of rentable floor area (“ Rentable Floor Area of the Fourth Expansion Premises A ”) as shown on Exhibit A , and the “ Fourth Expansion Premises B ,” which is 2,591 feet of rentable floor area (“ Rentable Floor Area of the Fourth Expansion Premises B ”) as shown on Exhibit A .

     Landlord and Tenant are entering into this instrument to set forth the terms and conditions for the use and occupancy of the Fourth Expansion Premises and to otherwise amend the Lease.

     NOW THEREFORE, in consideration of One Dollar ($1.00) and other good and valuable consideration in hand this date paid by each of the parties to the other, the receipt and sufficiency

of which are hereby severally acknowledged, and in further consideration of the mutual promises herein contained, Landlord and Tenant hereby agree to and with each other as follows:

1.		As of the “ Fourth Expansion Premises Commencement Date ” (as defined in Section 2 below) and continuing through the expiration or earlier termination of the Term (including the balance of the First Extended Term), the Existing Premises shall be expanded to include the Fourth Expansion Premises, such that the Existing Premises and the Fourth Expansion Premises shall constitute the “Premises” (and “Tenant’s Space”) demised to Tenant under the Lease. All terms and conditions of the Lease (including, without limitation, Tenant’s right to extend the Lease Term as set forth in Section 6 of the First Amendment) shall apply to the Fourth Expansion Premises and Existing Premises, collectively, except as otherwise indicated in this Fourth Amendment.
2.		The following definitions are hereby added (or substituted, where applicable) to the REFERENCE DATA in Section 1.1 of the Lease:

		FOURTH EXPANSION PREMISES COMMENCEMENT DATE:		The Effective Date.
		FOURTH EXPANSION PREMISES A RENT COMMENCEMENT
		DATE:		The earlier to occur of (i) March 1, 2008, or (ii) the date on which the Fourth Expansion Premises Work is substantially complete, as described in Section 7.2 below, or (iii) the date on which Tenant commences beneficial use of the Fourth Expansion Premises A for its business purposes.
		FOURTH EXPANSION PREMISES B RENT COMMENCEMENT
		DATE:		The earlier to occur of (i) March 1, 2008, or (ii) the date on which the Fourth Expansion Premises Work is substantially complete, as described in Section 7.2 below, or (iii) the date on which Tenant commences beneficial use of the Fourth Expansion Premises B for its business purposes.
		FOURTH EXPANSION PREMISES

		EXPIRATION DATE:		September 30, 2010, to be coterminous with the Term
		LANDLORD’S CONSTRUCTION REPRESENTATIVE:		Michael Schumacher
		TENANT’S CONSTRUCTION
		REPRESENTATIVE:		David Mann and Steven Wasserman, either of whom individually may act on Tenant’s behalf.
		BROKER:		McCall & Almy One Post Office Square, 37 th Floor Boston, Massachusetts 02109

3.		ANNUAL FIXED RENT .
		(A) With respect to the Existing Premises , Annual Fixed Rent shall be paid as currently provided in the Lease.
		(B) With respect to the Fourth Expansion Premises A , Annual Fixed Rent for the Fourth Expansion Premises A shall be payable as follows:

(i) Commencing on the Fourth Expansion Premises A Rent Commencement Date and continuing through and including September 2008 (plus the partial month, if any, immediately following the Fourth Expansion Premises A Rent Commencement Date) at the annual rate of Eight Hundred and Thirty Three Thousand Nine Hundred and Eighty Two 50/100 Dollars ($ 833,982.50 ) (being the product of (i) $ 32.50 and (ii) the Rentable Floor Area of the Fourth Expansion Premises A (being 25,661 square feet));

(ii) During the next twelve (12) calendar months of the Term, at the annual rate of Eight Hundred and Fifty Nine Thousand Six Hundred and Forty Three 50/100 Dollars ($ 859,643.50 ) (being the product of (i) $ 33.50 and (ii) the Rentable Floor Area of the Fourth Expansion Premises A); and

(iii) Thereafter and continuing through the expiration of the Term, at the annual rate of Eight Hundred and Eighty Five Thousand Three Hundred and Four 50/100 Dollars ($ 885,304.50 ) (being the product of (i) $ 34.50 and (ii) the Rentable Floor Area of the Fourth Expansion Premises A).

(C) With respect to the Fourth Expansion Premises B , Annual Fixed Rent for the Fourth Expansion Premises B shall be payable as follows:

(i) Commencing on the Fourth Expansion Premises B Rent Commencement Date and continuing and continuing through and including September 2008 (plus the partial month, if any, immediately following the Fourth Expansion Premises B Rent Commencement Date) at the annual rate of Sixty Nine Thousand Nine Hundred and Fifty Seven 00/100 Dollars ($ 69,957.00 ) (being the product of (i) $ 27.00 and (ii) the Rentable Floor Area of the Fourth Expansion Premises B (being 2,591 square feet));

(ii) During the next twelve (12) calendar months of the Term, at the annual rate of Seventy Two Thousand Five Hundred and Forty Eight 00/100 Dollars ($ 72,548.00 ) (being the product of (i) $ 28.00 and (ii) the Rentable Floor Area of the Fourth Expansion Premises B); and

(iii) Thereafter and continuing through the expiration of the Term, at the annual rate of Seventy Five Thousand One Hundred and Thirty Nine 00/100 Dollars ($ 75,139.00 ) (being the product of (i) $ 29.00 and (ii) the Rentable Floor Area of the Fourth Expansion Premises B).

4.

Effective as of the Fourth Expansion Premises Commencement Date and continuing through the expiration of the Term, the following definitions are hereby added to the REFERENCE DATA in Section 1.1 of the Lease:

NUMBER OF PARKING PRIVILEGES FOR THE FOURTH EXPANSION PREMISES:		Beginning on the Fourth Expansion Premises Commencement Date, there shall be added additional privileges for parking ninety nine (99) automobiles, twenty-eight (28) of which are located in the garage below the Building, and seventy-one (71) of which will be located on the outdoor surface lot.
RENTABLE FLOOR AREA OF THE FOURTH EXPANSION PREMISES A:		25,661 square feet.
RENTABLE FLOOR AREA OF THE FOURTH EXPANSION PREMISES B:		2,591 square feet.

5.

OPERATING EXPENSES .

		(A) Existing Premises . For purposes of calculating Tenant’s payments for Operating Expenses for the Existing Premises pursuant to Section 2.6 of the Lease, the definition of “Base Operating Expenses” shall be unchanged.
		(B) Fourth Expansion Premises . In addition to the payments referenced in Section 5(A) above, Tenant shall pay Operating Expenses for the Fourth Expansion Premises to be calculated as follows: For purposes of calculating Tenant’s payments for Operating Expenses for the Fourth Expansion Premises pursuant to Section 2.6 of the Lease for that portion of the Term on and after the Fourth Expansion Premises Commencement Date, with respect to the Fourth Expansion Premises only , the definition of “Base Operating Expenses” shall be:

		BASE OPERATING EXPENSES:		Landlord’s Operating Expenses (as defined in Section 2.6 of the Lease) for calendar year 2008 being January 1, 2008 through December 31, 2008.

		(C) Notwithstanding the foregoing or any provision hereof to the contrary, Tenant shall not be obligated to pay any of Landlord’s Operating Expenses allocable to the Fourth Expansion Premises for any period prior to January 1, 2009.
6.		REAL ESTATE TAXES .
		(A) Existing Premises . For purposes of calculating Tenant’s payments for real estate taxes for the Existing Premises pursuant to Section 2.7 of the Lease, the definition of “Base Taxes” shall be unchanged.
		(B) Fourth Expansion Premises . In addition to the payments referenced in Section 6(A) above, Tenant shall pay real estate taxes for the Fourth Expansion Premises to be calculated as follows: For purposes of calculating Tenant’s payments for real estate taxes for the Fourth Expansion Premises pursuant to Section 2.7 of the Lease for that portion of the Term on and after the Fourth Expansion Premises Commencement Date, with respect to the Fourth Expansion Premises only , the definition of “Base Taxes” shall be:

		BASE TAXES:		Landlord’s Tax Expenses (as defined in Section 2.7 of the Lease) for fiscal tax year 2008 being July 1, 2007 through June 30, 2008.

(C)Notwithstanding the foregoing or any provision hereof to the contrary, Tenant shall not be obligated to pay any of Landlord’s Tax Expenses allocable to the Fourth Expansion Premises for any period prior to July 1, 2008.

7.0		Condition of the Fourth Expansion Premises . Tenant shall accept the Fourth Expansion Premises in its “AS-IS” condition without any obligation on the Landlord’s part to perform any additions, alterations, improvements, demolition or other work therein or pertaining thereto or to install or connect any of Tenant’s telephone or other communications equipment or systems or to provide any allowance, except as provided below. Notwithstanding the foregoing, Landlord represents and warrants that as of the Fourth Expansion Premises Commencement Date, the HVAC system and all other building systems serving the Fourth Expansion Premises (excluding all of the supplemental systems serving the existing data center located in the Fourth Expansion Premises A) will be in good order, condition and repair. Notwithstanding the foregoing, in the event that a supplemental system serving the above-referenced data center also serves (in common with the data center) some other portion of the Fourth Expansion Premises (hereinafter, the “non-data center portion of the Fourth Expansion Premises”), the Landlord will be responsible for putting such supplemental system in good order, condition and repair only with respect to its ability to serve the non-data center portion of the Fourth Expansion Premises, and Landlord shall have no obligation or liability in connection with the ability of said supplemental systems to serve the data center.
7.1		Fourth Expansion Premises Work
		(A) Tenant, at its sole cost and expense, shall perform all work necessary to prepare the Fourth Expansion Premises for Tenant’s occupancy (the “ Fourth Expansion Premises Work ”). Landlord acknowledges that it has approved the work described on the schematic plans attached hereto as Exhibit B (the “ Tenant’s Schematic Plans ”). The Fourth Expansion Premises Work shall be performed in accordance with plans and specifications prepared by an architect, licensed by the Commonwealth of Massachusetts and reasonably approved by Landlord (the “ Fourth Expansion Premises Architect ”), such plans and specifications to be subject to the reasonable approval of the Landlord, but Landlord may not disapprove of matters shown on and consistent with the Tenant’s Schematic Plans. Without limiting the generality of the foregoing, Tenant shall have the right to use Visnick & Caulfield Associates, Inc. as the Fourth Expansion Premises Architect for the Fourth Expansion Premises Work. Tenant shall submit to Landlord, a detailed floor plan layout together with working drawings for the Fourth Expansion Premises Work to prepare the Fourth Expansion Premises for Tenant’s occupancy. Such floor plan layout and working drawings (the “ Fourth Expansion Premises Plans ”) shall contain at least the information required by, and shall conform to the requirements of, Exhibit B to the Third Amendment. Provided that the Fourth Expansion Premises Plans contain at least the information required by, and conform to the requirements of, said Exhibit B, Landlord’s approval of the Fourth Expansion Premises Plans shall not be unreasonably withheld or delayed (said approval to be given within five (5) business days of Landlord’s receipt of three (3) copies of such plans and specifications); however, Landlord’s determination of matters relating to aesthetic issues relating to alterations or changes which are visible outside the Premises shall be in Landlord’s sole discretion. If

		Landlord disapproves of any Fourth Expansion Premises Plans, then Tenant shall promptly have the Fourth Expansion Premises Plans revised by the Fourth Expansion Premises Architect to incorporate all objections and conditions presented by Landlord and shall resubmit such plans to Landlord no later than seven (7) days after Landlord has submitted to Tenant its objections and conditions. Such process shall be followed until the Fourth Expansion Premises Plans shall have been approved by the Landlord without objection or condition.
		(B) Once the Fourth Expansion Premises Plans have been approved by Landlord, Tenant, at its sole cost and expense, shall promptly, and with all due diligence, perform the Fourth Expansion Premises Work as set forth on the Fourth Expansion Premises Plans, and, in connection therewith, Tenant shall obtain all necessary governmental permits and approvals for the Fourth Expansion Premises Work.
7.2		Quality and Performance of Work
		All of the Fourth Expansion Premises Work shall be performed strictly in accordance with Section 3.3 of the Lease. Tenant shall have the Fourth Expansion Premises Work performed by contractors, reasonably approved by Landlord, which contractors shall provide to Landlord such insurance as the Landlord may reasonably require. Without limiting the generality of the foregoing, and subject to all applicable terms and conditions of the Lease, Tenant shall have the right to use Majestic Construction, Inc., as the general contractor for the Fourth Expansion Premises Work. Landlord shall have the right to provide such reasonable rules and regulations relative to the performance of the Fourth Expansion Premises Work and