Exhibit 10.13.6





CONFIDENTIAL TREATMENT REQUESTED





AMENDMENT NUMBER FIVE TO GOOGLE SERVICES
AGREEMENT



This Amendment Number
Five to the Google Services Agreement (“Amendment”) is effective as of August 1, 2014(“Amendment
Effective Date”), and amends the Google Services Agreement by and between Synacor, Inc. (“Company”)
and Google Inc. (“Google”) with an effective date of March 1, 2011, as amended (the “Agreement”).
Capitalized terms not defined in this Amendment have the meanings given to those terms in the Agreement. The parties agree as follows:



| | 1. | Additional Definitions. The following are
added as new Sections 1.31-1.36:
| | -- | --------------------------------------------------------------------------



“1.31 ‘[*]AFS Ads’ means AFS Ads that are displayed in response to Search Queries submitted by End Users [*].



1.32  ‘[*]AFS Ads’
means AFS Ads displayed in response to Search Queries submitted by End Users [*].



1.33 [*]



1.34 [*]



1.35  ‘[*]AFS Ads’
means AFS Ads displayed in response to Search Queries submitted by End Users [*].”



1.36 [*]



| | 2. | Implementation and Maintenance. Sections
2.2(d) and 2.2(e) are deleted in their entirety and replaced by the following:
| | -- | -----------------------------------------------------------------------------------------------------------------------



“2.2(d) Subject to
Section 2.3[*],Company will ensure that (i) every Search Query generates a WS Request, (ii) every Request is generated
by a Search Query and (iii) every Request contains the Search Query that generated that Request.



2.2(e) For each AFS Request,
Company will request at least [*] wide format [*] AFS Ads,[*].”



| | 3. | AFS Search Queries. Section 2.3 is deleted
in its entirety and replaced with the following:
| | -- | -------------------------------------------------------------------------------------------



“2.3. [*]



| | 4. | Exhibit B. Exhibit B is deleted in its
entirety and replaced with Exhibit B attached to this Amendment.
| | -- | -------------------------------------------------------------------------------------------------------



| | 5. | General. The parties may execute this Amendment
in counterparts, including facsimile, PDF, or other electronic copies, which taken together will constitute one instrument. Except
as expressly modified herein, the terms of the Agreement remain in full force and effect.
| | -- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------





[*] = CERTAIN INFORMATION HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.









CONFIDENTIAL TREATMENT REQUESTED





IN WITNESS WHEREOF, the parties have executed this Amendment
by persons duly authorized.





|GOOGLE |                                                  | SYNACOR, INC.
|------ | ------------------------------------------------ | -------------
|       |                                                  |              
|By:    | /s/ Nikesh Arora                                 |              
|Name:  | Nikesh Arora                                     |              
|Title: | President, Global Sales and Business Development |              
|Date:  | August 15, 2014                                  |              











CONFIDENTIAL TREATMENT REQUESTED





EXHIBIT B

AFS Revenue Share Percentage



[*]





[*] = CERTAIN INFORMATION HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.