Lease by Constant Contact, Inc.

EXHIBIT 10.2

55 MIDDLESEX TURNPIKE

OFFICE SPACE RIDER

Between

DIGITAL 55 MIDDLESEX, LLC

as Landlord

and

CONSTANT CONTACT, INC.

as Tenant

Dated

May 11, 2012

SCHEDULE “1”

CERTAIN DEFINED TERMS

“Building Office Standard” shall mean and refer to the type, grade, quantity and design of materials and construction as are customarily utilized by Landlord in the Building for the construction of “garden-variety” office uses.

“Landlord” shall mean and refer to the Landlord set forth in Item 1 of the Basic Rider Information.

“Landlord’s OS Installations” shall mean and refer to the installations defined as such, as set forth on Exhibit “E”, attached hereto.

“Landlord’s OS Repair Obligations” shall mean and refer to Landlord’s obligations to arrange for the repair and maintenance of the foundation, exterior walls and roof of the Building; the Common Areas within the Building; and the HVAC systems serving the OS Premises and/or the Common Areas of the Building.

“Lease” shall mean that certain Datacenter Lease related to Suites 405, 407, 409, 418A in the Building, having an Effective Date of January 1, 2011, by and between Landlord and Tenant, as amended from time to time.

“Maximum Structural Load - OS” shall mean and refer to the Maximum Structural Load - OS set forth in Item 12 of the Basic Rider Information.

“New OS Tenant Space” shall mean the premises to which the OS Tenant Space is being relocated and re-assigned pursuant to Section 1.4 of the Standard Rider Provisions.

“OS Base Rent” shall mean and refer to the amounts of OS Base Rent set forth in Item 6 of the Basic Rider Information.

“OS Demising Walls” shall mean and refer to Building Office Standard drywall office demising walls.

“OS Electrical Metering Equipment” shall mean and refer to a Building Office Standard electrical metering device (or electrical metering devices) compatible with Landlord’s energy management system for monitoring electricity provided to and/or used in the OS Tenant Space.

“OS Electricity Consumption Threshold” shall mean and refer to the amount of electrical power specified in Item 11 of the Basic Rider Information.

“OS Permitted Use” shall mean and refer to the OS Tenant Space being used only for general office purposes in accordance with Applicable Law.

“OS Rider Term” shall mean and refer to the period described in Item 4 of the Basic Rider Information, subject to the terms of such Item 4.

“OS Rules and Regulations” shall mean and refer to Landlord’s rules and regulations for the OS Tenant Space, as same may be amended from time to time by Landlord in Landlord’s reasonable discretion.

“OS Tenant Space” shall mean and refer to the OS Tenant Space set forth in Item 5 of the Basic Rider Information.

“Tenant” shall mean and refer to the Tenant set forth in Item 2 of the Basic Rider Information.

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55 MIDDLESEX TURNPIKE

OFFICE SPACE RIDER

This Office Space Rider (this “Rider”) is entered into as of the OS Effective Date by and between Landlord and Tenant with reference to the following:

R E C I T A L S

A. Tenant leases Tenant Space in the Building from Landlord pursuant to the Lease.

B. Landlord desires to lease to Tenant certain office space within the Building and Tenant desires to lease such space, pursuant to the terms and conditions of this Rider.

C. Unless otherwise specifically indicated to the contrary, all initially capitalized terms contained in this Rider shall have the meanings set forth on Schedule “1”, attached to this Rider. All initially capitalized terms contained in this Rider, but not otherwise defined in this Rider, shall have the meanings ascribed to them in the Lease.

NOW, THEREFORE, in consideration of the covenants and agreements hereinafter set forth, Landlord and Tenant agree to the following terms of this Rider, which shall supplement the Lease as of the OS Effective Date:

BASIC RIDER INFORMATION

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This Rider shall consist of the foregoing Basic Rider Information, and the provisions of the Standard Rider Provisions below “Schedule 1”, above, and Exhibits “A” through “G”, all of which are incorporated herein by this reference as of the OS Effective Date. In the event of any conflict between the provisions of the Basic Rider Information and the provisions of the Standard Rider Provisions, the Basic Rider Information shall control.

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STANDARD RIDER PROVISIONS

1. OS TENANT SPACE.

1.1 OS Tenant Space. Upon and subject to the terms and conditions of this Rider, the Lease is hereby modified to reflect that Landlord does hereby lease, demise and let unto Tenant and Tenant does hereby lease from Landlord the OS Tenant Space, to have and to hold for the OS Rider Term.

1.2 Condition of OS Tenant Space. Tenant agrees that, subject to Landlord’s completion of Landlord’s OS Installations, Tenant shall be deemed to have accepted the OS Tenant Space in its “AS IS, WHERE IS” condition on the OS Commencement Date. Except for Landlord’s OS Installations, Landlord shall have no obligation to perform any work in the OS Tenant Space (including, without limitation, demolition of any improvements existing therein or construction of any tenant finish-work or other improvements therein), and Landlord shall not be obligated to reimburse Tenant or provide an allowance for any costs related to the demolition or construction of improvements therein. Tenant acknowledges that, except as expressly set forth herein, no representation or warranty (express or implied) has been made by Landlord as to the condition of the OS Tenant Space or its suitability or fitness for Tenant’s intended purpose.

1.3 Delivery of OS Tenant Space. Landlord shall use commercially reasonable efforts to cause Landlord’s OS Installations to be completed prior to the OS Commencement Date. In the event, however, that Landlord’s OS Installations have not been completed by the OS Commencement Date, Landlord shall not be deemed in default hereunder, provided that Landlord is working diligently using commercially reasonable efforts after the OS Commencement Date to complete the installation of Landlord’s OS Installations.

1.4 Rights Reserved to Landlord. Landlord reserves the right to relocate the OS Tenant Space to some other space of Landlord’s choosing of approximately the same dimensions and size within the Building without effecting an eviction or disturbance of Tenant’s use or possession or giving rise to any claim for setoffs or abatement of OS Base Rent due under this Rider; provided, however, that if Landlord exercises Landlord’s option to remove and relocate Tenant in the New OS Tenant Space, then Tenant shall be required to pay the same per square foot rates of OS Base Rent, as is represented in this Rider. Nothing herein contained shall be construed to relieve Tenant, or imply that Tenant is relieved,

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