Note 11—Segment Information

The Company has organized its business into two operating segments based on the product specialties: the vascular segment and the dermatology segment.

In deciding how to allocate resources and assess performance, the Company’s chief operating decision maker regularly evaluates the sales and gross profit of these segments. Amounts included within selling, general and administrative expense and research and development expense are general to the Company and not specific to a particular segment; therefore, these amounts are not evaluated by the Company’s chief operating decision maker on a segmented basis.

The following tables summarize segment performance (in thousands):

Generally, all assets are common assets, except for demonstration lasers and lasers placed with customers, which are a subset of property and equipment. The net book value of demonstration lasers and lasers placed with customers aggregated in the vascular segment was $2.6 million and $2.2 million as of March 31, 2019 and December 31, 2018, respectively. The net book value of the demonstration lasers and lasers placed with customers aggregated in the dermatology segment was $0.9 million and $0.7 million as of March 31, 2019 and December 31, 2018, respectively.

No sales to an individual customer or country other than the United States accounted for more than 10% of net revenue for the three months ended March 31, 2019 and 2018. Net revenue, classified by the major geographic areas in which our customers are located, was as follows: