12. Segments

The Company aligns its operating segments in order to conform to management’s internal reporting structure, which is reflective of service offerings by industry. Management aggregates such operating segments into two reporting segments: what consumers buy (“Buy”), consisting principally of market research information and analytical services; and what consumers watch (“Watch”), consisting principally of television, radio, online and mobile audience and advertising measurement and corresponding analytics.

Corporate consists principally of unallocated items such as certain facilities and infrastructure costs as well as intersegment eliminations. Certain corporate costs, other than those described above, including those related to selling, finance, legal, human resources, and information technology systems, are considered operating costs and are allocated to the Company’s segments based on either the actual amount of costs incurred or on a basis consistent with the operations of the underlying segment. Information with respect to the operations of each of Nielsen’s business segments is set forth below based on the nature of the services offered and geographic areas of operations.

Business Segment Information

(IN MILLIONS)	Buy		Watch		Corporate				Total
Three Months Ended September 30, 2017
Revenues	$	803	$	838	$		—		$	1,641
Depreciation and amortization	$	53	$	106	$	1			$	160
Restructuring charges	$	4	$	2	$	1			$	7
Stock-based compensation expense	$	3	$	2	$	3			$	8
Other items⁽¹⁾	$	—	$	—	$	10			$	10
Operating income/(loss)	$	85	$	280	$	(28		)	$	337
Business segment income/(loss)⁽²⁾	$	145	$	390	$	(13		)	$	522
Total assets as of September 30, 2017	$	6,925	$	9,706	$	(46		)	$	16,585

(IN MILLIONS)
Three Months Ended September 30, 2016
Revenues	$	809	$	761	$		—		$	1,570
Depreciation and amortization	$	53	$	97	$	1			$	151
Restructuring charges	$	15	$	2	$	12			$	29
Stock-based compensation expense	$	3	$	2	$	6			$	11
Other items⁽¹⁾	$	—	$	—	$	11			$	11
Operating income/(loss)	$	79	$	259	$	(42		)	$	296
Business segment income/(loss)⁽²⁾	$	150	$	360	$	(12		)	$	498
Total assets as of December 31, 2016	$	6,697	$	8,905	$	128			$	15,730

(IN MILLIONS)	Buy		Watch		Corporate			Total
Nine months Ended September 30, 2017
Revenues	$	2,383	$	2,428	$	—		$	4,811
Depreciation and amortization	$	156	$	318	$	3		$	477
Restructuring charges	$	31	$	9	$	8		$	48
Stock-based compensation expense	$	10	$	9	$	16		$	35
Other items ⁽¹⁾	$	—	$	—	$	28		$	28
Operating income/(loss)	$	219	$	734	$	(85	)	$	868
Business segment income/(loss) ⁽²⁾	$	416	$	1,070	$	(30	)	$	1,456

(IN MILLIONS)
Nine months Ended September 30, 2016
Revenues	$	2,454	$	2,199	$	—		$	4,653
Depreciation and amortization	$	158	$	289	$	3		$	450
Restructuring charges	$	42	$	7	$	24		$	73
Stock-based compensation expense	$	12	$	7	$	18		$	37
Other items ⁽¹⁾	$	2	$	2	$	24		$	28
Operating income/(loss)	$	216	$	684	$	(98	)	$	802
Business segment income/(loss) ⁽²⁾	$	430	$	989	$	(29	)	$	1,390

(1)	Other items primarily consist of transaction related costs and business optimization costs for the three and nine months ended September 30, 2017. Other items primarily consist of business optimization costs for the three and nine months ended September 30, 2016.

(2)	The Company’s chief operating decision maker uses business segment income/(loss) to measure performance from period to period both at the consolidated level as well as within its operating segments.