NOTE 4—REVENUES

Revenues by category were as follows (in thousands):

The following table summarizes the revenue allowance and accrual activities for the years ended December 31, 2019 and 2018 (in thousands):

The following table sets forth information regarding customers that accounted for 10% or more of net revenues and account receivables:

The Company is party to a distributor agreement with Telcon pursuant to which it granted Telcon exclusive rights to the Company’s PGLG oral powder for the treatment of diverticulosis in South Korea, Japan and China in exchange for Telcon’s payment of a $10 million upfront fee and agreement to purchase from us specified minimum quantities of the finished product. In a related license agreement with Telcon, the Company agreed to use commercially reasonable best efforts to obtain product registration in these territories within three years of obtaining FDA marketing authorization for PGLG in this indication. Telcon has the right to terminate the distributor agreement in certain circumstances for failure to obtain such product registrations, in which event the Company would be obliged to return to Telcon the $10 million upfront fee. The upfront fee of $10 million is included in other long-term liabilities as unearned revenue as of December 31, 2019 and 2018. Refer Note 13 for related party transaction details.  

The Company received an upfront payment of $500,000 in connection with entering into a distribution agreement with a strategic partner in 2018 to distribute Endari® in the Middle East and North Africa region. The payment was recorded as unearned revenue and included in other long-term liabilities to be recognized as revenue when the performance obligations are satisfied. The upfront payment of $500,000 is included in other long-term liabilities as unearned revenue as of December 31, 2019 and 2018.