REVENUE

Company revenue is primarily comprised of MRO product sales and related activities, such as freight and services. Total service revenue is not material and accounted for approximately 1% of the Company revenue for the three months ended March 31, 2019 and 2018, respectively.

Grainger serves a large number of customers in diverse industries, which are subject to different economic and market specific factors. The Company's presentation of revenue by industry most reasonably depicts how the nature, amount, timing and uncertainty of Company revenue and cash flows are affected by economic and market specific factors. The

following table presents the Company's percentage of revenue by reportable segment and by major customer industry:



	Three Months Ended March 31,
	2019						2018
	U.S.		Canada		Total Company (2)		U.S.		Canada		Total Company (2)
Government	17	%	6	%	13	%	17	%	7	%	13	%
Heavy Manufacturing	19	%	21	%	18	%	20	%	20	%	19	%
Light Manufacturing	13	%	6	%	11	%	13	%	5	%	11	%
Transportation	6	%	8	%	5	%	5	%	8	%	5	%
Commercial	17	%	9	%	14	%	16	%	10	%	13	%
Retail/Wholesale	8	%	4	%	7	%	8	%	4	%	7	%
Contractors	10	%	10	%	8	%	10	%	12	%	8	%
Natural Resources	3	%	32	%	4	%	3	%	31	%	4	%
Other (1)	7	%	4	%	20	%	8	%	3	%	20	%
Total net sales to external customers	100	%	100	%	100	%	100	%	100	%	100	%
Percent of Total Company Revenue	72	%	5	%	100	%	72	%	7	%	100	%

(1) Other category primarily includes revenue from individual customers not aligned to major industry segment, including small businesses and consumers and intersegment net sales.

(2) Total Company includes other businesses, which include the Company's endless assortment businesses and operations in Europe, Asia and Latin America and account for approximately 23% and 21% of revenue for the three months ended March 31, 2019 and 2018, respectively.

Total accrued sales returns were approximately $27 million and $29 million as of March 31, 2019 and December 31, 2018 and are reported as a reduction of Accounts receivable. Total accrued sales incentives were approximately $51 million and $62 million as of March 31, 2019 and December 31, 2018 and are reported as part of Accrued expenses. The Company did not have any material unsatisfied performance obligations, contract assets or liabilities as of March 31, 2019 and December 31, 2018.