Note 8 - Concentrations (Tables)

12 Months Ended

Mar. 31, 2018

Notes Tables

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]

	% of Revenue for Year Ended March 31
	2018		2017		2016
Customer A		19%		22%		23%
Customer B		18%		20%		20%

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

	Year Ended March 31
	2018		2017		2016
United States	$	14,911,258	$	13,600,236	$	12,392,053
Europe, the Middle East, and Africa		10,133,134		9,612,883		11,392,046
Asia-Pacific		4,607,811		4,200,934		3,113,484
Rest of World		211,678		912,143		819,695
Total Revenue	$	29,863,881	$	28,326,196	$	27,717,278