Repligen employs a direct sales model to users of its products in the United States, with some sales through intermediaries in "certain foreign markets".
As a result of royalty-generating out-licensing, royalty revenue from Bristol-Myers Squibb has been in the 27% to 37% range as a proportion of total revenue during the 2010-2013 period; in comparison to revenue from sales, the largest customer accounted for 35% to 45% of revenue during the same period.